NYZ – Unknowable Determinism

I wrote a blurb for the new album Unknowable Determinism by NYZ (Dave Burraston). The album comprises tracks made from 2013 to 2016, marking a significant new direction for NYZ, based on an original approach to mapping between cellular automata rules and tuning systems. The term ‘unknowable determinism’ was coined by Ed Fredkin, a physicist who developed Konrad Zuse’s idea that the universe is a digital computer. This is an idea that both Dave and I came across, separately, through our research into cellular automata. Zuse explored whether it was possible establish a theory of physics that is digital, i.e. discrete and finite, as opposed to continuous and infinite. If classical physics is ‘analog’ (e.g. Newton’s laws of motion), and quantum physics is both ‘analog’ and ‘digital’ (e.g. wave/particle duality), could there be a purely digital physics? In a paper (1967) and book (1969) called Rechnender Raum [Calculating Space], Zuse suggested that this could take the form of a cellular automaton [PDF available here: ftp://ftp.idsia.ch/pub/juergen/zuserechnenderraum.pdf]. Fredkin developed this hypothesis into a theory of digital physics that he calls Finite Nature:

Uncertainty is at the heart of quantum mechanics. Finite Nature requires that we rule out true, locally generated randomness because such numbers would not, in this context, be considered finite. The reason is that there is no way to create, within a computer, a truly random number that is orthogonal to everything in the computer. On the other hand, another kind of randomness appears in CA where the values of many of the bits are so influenced by distant events as to be essentially orthogonal to any local process. The deterministic nature of finite digital processes is different in that it is unknowable determinism. From within the system an observer will never be able to know very much about the true microscopic state of that system. Every part of space is computing its future as fast possible, while information pours in from every direction. The result is the same as caused by the apparent randomness of quantum mechanical processes. (Fredkin, 1992, Finite Nature. http://www.ai.mit.edu/projects/im/ftp/poc/fredkin/Finite-Nature)

So ‘unknowable determinism’ characterizes both a complex system and [the limits to] our knowledge of it. It means that we cannot hope to predict how such a system might evolve, even if we understand the computations involved. And it is perceptually indistinguishable from randomness, which is also causal yet unpredictable. It applies not only to the concept of digital philosophy but also to the cellular automata systems that Dave designed and used to make this album, through which he wrangles a selection of CA rules and translates their computations into musical information.

Unknowable Determinism will be released on 15 May 2021 via Stellage. Listen to excerpts, read the blurb, and pre-order the album here: https://stellage.store/collection/cd/product/unknowable-determinism

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Tokinogake, a Japanese label, asked me to make a list of five tracks I like. I picked some folk songs. You might like them too: https://www.tokinogake.com/post/5tracks-guy-birkin—folk-song There are two other lists so far, one by a0n0 and the other by IKTS.

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I spent a lot of time with music in 2020. Most of what I listened to has been confrontational rather than contemplative, something to combat what the year has thrown at us, rather than the ‘balm for troubled times’ variety, but there’s been plenty of that too, with both old-and-familiar and old-but-new-to-me music. I bought only 3 or 4 physical copies of albums but on my hard drive I’ve got around 8 and half days worth of music that was released this year alone. These are some of the things I enjoyed the most.

{arsonist} – Reality Structure. I like this album a lot. Probably one of the most melodic and definitely one of the most emotionally engaging. It includes glitchy textures, generative patterns, saxophone and choral strings, and it literally ends with a bang as the final track bursts into percussion that sounds like fireworks, turning what’s quite a sad atmosphere into something more hopeful.

Maryanne Amacher (19382009) was an artist whose name I knew but not her work. Amacher made some incredible sounds, and specialized in otoacoustic emmissions (OAEs) – sounds generated in and by the ear itself. Sound Characters (Making The Third Ear) (1999) mainly features sounds that generate different kinds of OAEs, while Sound Characters 2 (Making Sonic Spaces) (2008) uses the same techniques more sparingly in fewer, longer pieces. Marcin Pietruszewski recommended this article by David Kemp, ‘Otoacoustic Emissions: Concepts and Origins’, as a good summary of the subject.

Autechre‘s DJ stream on Mixlr was one of my favourite things this year. It was a nice surprise, and it became a daily occurrence for a while. Much of the music they played was their own favourites and influences, with different genres on different days, and some newer music, like William Fields, Kindohm and SDEM, as well as some of their own previously unreleased stuff. They also streamed on Twitch, showing one of their systems that uses video as input to generate and control the music. The online chat provided a sense of community during the first lockdown in March, and when they streamed SIGN just before it was released. SIGN doesn’t follow the trajectory implied by previous albums, which was going towards more messed up beats, more complex sounds, more different styles within and across tracks, and increasing durations. It’s lush, melodic and concise and it repays repeated listening because there’s a lot going on under the surface: the sounds appear to be the residue of a complicated process of creation and erasure, an auditory palimpsest bearing traces of each modification. ‘Metaz form8’ (track 6) and ‘r cazt’ (the final track) are the tracks that catch my ear, not because they’re loud or intrusive, but because of their gentle intensity and emotional potency. PLUS was a nice surprise addition but is more like what you’d expect the new album to sound like, and that’s why I prefer SIGN. When I bought them from AE_STORE, I discovered Sinistrail Sentinel (2018) in my downloads – apparently given to those who bought the CD version of NTS Sessions, but I’d never noticed it. A final treat was the replication of Autechre’s 2008 live set at Echoplex by two fans, ios and digit, who spent a lot of time and effort working with the synth patches and sysex files that had been made available via a hidden link on the website.

Of all the musicians who sadly died this year, the one that hit me hardest was Mr Chi Pig (Ken Chinn), singer of SNFU, a band that’s been a favourite since my teens. He wrote from experience about the pains of everyday life and love, about mental illness and addiction. I got to speak to him once after a gig at Derby Wherehouse in the 90s. As a frontman, Chi Pig was one of the best.

Akira Sileas is one of my favourite new artists, discovered through a recommendation by Mylar Melodies, and I’ve bought everything they’ve made since then. Under the name AB-607 are two EPs of extended acid tunes, both released on cassette. Under their own name are more experimental sounds made with physical modelling algorithms and pure data patches.

De Forrest Brown Jr published How Platform Capitalism Devalued the Music Industry, an article commissioned and then rejected by Resident Advisor. As Speaker Music he made the vital album Black Nationalist Sonic Weaponry (Planet Mu) that comes with a booklet of text and images by Brown and other artists. Like Percussive Therapy, the EP that preceded it, this album is made of brutal, broken beats, but instead of therapeutic benefits it offers protest music and contextual information to counter ignorance and discrimination. This is an example of the politicization of art as a counter-response to the aestheticization of politics which Walter Benjamin described in the essay The Work of Art in the Age of Mechanical Reproduction [PDF]

Dave Burraston started a Bandcamp subscription which I signed up to straight away, with loads of existing albums available, plus new and old work added regularly. As NYZ he released his first albums with beats – OLD TRX (87-93) (Death of Rave) and CCD (FLUF), as well as more meditative drones, like a split with ELEH (Important Records). Dave was also part of Knob Twiddler’s Hangout #30, hosted by Jochem Paap (Speedy J), along with Vincent Koreman (Drvg Cvltvre, New York Haunted) and Stephen McEvoy (TUUUN, FLUF), where he talked about working on the presets for AFX Station and how he developed the rainwire environmental sonification system.

In Workaround (PAN), Beatrice Dillon constructs pieces of music that balance extreme high and low frequencies in simple parts that make complex and unusual rhythms. This is a really impressive album, and I listen to it a lot.

Do/While – a DJ live stream by Dan and Wonja archived on SoundCloud. Usually on Sunday night, it’s a nice end to the weekend with some relaxed beats and tunes. Alita the dog usually features on the video stream, lolling on the rug and playing with toys. Dan and Wonja also set up Sound.Rodeo, a message board for sharing rips of hard-to-find and out-of-print music.

Do/While 13/12/2020

Boomkat’s Documenting Sound series of tapes is one of many examples of productive and creative responses to what’s been a terrible year for musicians. Some of my favourites in the series are Mark Leckey, Dean Hurley, Lucy Railton and FUJI||||||||||TA. Another series I enjoyed is Touch: Isolation including Chris Watson, Jana Winderen, ELEH and Claire M. Singer

The members of farmersmanual have been busy putting out old and new music as a group, as solo artists and in collaborations with others. Through their generate and test label they released General Magic’s 2005 performance as The Bratislava File, which is as much industrial metal as glitchy computer music, and Entrée Contrôle by Sluta Leta which combines vocals and retro synths, a bit like Finlay Shakespeare’s album Solemnities (Editions Mego) which I also liked a lot. 11​.​84​.​0​.​-​1​.​0​-​1​.​1​-​1 is an album that started with a single initial track, and each time someone bought the album a new track was generated, based on the initial one, until it reached 100 tracks. Another favourite is flowers a sun hazy by dprmkr, a live session from 1997 with an 808 recorded to digital tape.

FRKTL – Excision After Love Collapses. A complex album of electronic music made with a variety of different methods: field recording, live instruments, generative beats, vocal samples and digital processing.

Darryl Hall & John Oates – Abandoned Luncheonette (1973). A Sunday morning kind of album, one that makes you feel better. I got this for research purposes, while collecting music that features Bernard Purdie on drums, because I’ve been working on a data sonification that uses the Purdie Shuffle. Other favourite albums featuring Bernard Purdie include Young, Gifted and Black by Aretha Franklin and Yusef Lateef’s Detroit.

Eiko Ishibashi – ORBIT (SUPERPANG). The second of three tracks, ‘WE ARE BUILT’, combines arpeggiated synths with snippets of field recordings featuring human voices. It’s one of my favourite tracks this year.

When I met up with Dave Burraston last year, he recommended Nightclubbing (1981) by Grace Jones. Coincidentally, my granny’s name was Grace Jones, although her friends called her ‘Gem’, short for her full name – Grace Edith May. I’d always liked what I’d heard of Grace Jones’ music but hadn’t listened to any albums in full. When Autechre played ‘Feel Up’ from Nightclubbing on their Mixlr stream, it prompted me get the album as Dave had suggested. He wasn’t wrong. It’s got a really good sound, recorded with Sly and Robbie at Chris Blackwell’s Compass Point Studios in the Bahamas. At the Grace Before Jones exhibition at Nottingham Contemporary art gallery I got to see some of the studio’s master tapes for her Fame album and the log sheets that record the positions of all the knobs and sliders on the mixing desk. Nightclubbing has been on my MP3 player most of the year.

Phil Julian – Carrier Dynamics (fancyyyyy). Recorded at Ina-GRM studios using their Serge Modular system, this is the kind of weird synthesized sound I like. Also really nice artwork/poster designed by Renick Bell.

Atte Elias Kantonen made 3 albums that I very much enjoyed. Studies in Audio Fabrics (Granny Records) is developed from research into the perception of auditory textures. The way that the electronic sounds chirp, groan and growl reminds me of Rashad Becker’s Traditional Music of Notional Species. Similarly, Frankille (Active Listener’s Club) and Nom Occasions (SUPERPANG) explore synthetic sounds produced/composed in such a way that they seem animalistic rather than mechanical or rational.

Nakul Krishnamurthy has previously collaborated with Mark Fell on projects and live performances exploring the intersections between the systems of Carnatic music and generative/algorithmic music. Tesserae (Takuroku) is Krishnamurthy’s first solo album, comprising two tracks that would each fit on one side of vinyl. The first track, ‘Anudhatthamudhatthassvaritham’, builds layers of vocal and string drones into a swirling mass, like a Hindustani version of Arvo Part’s Cantus in Memoriam Benjamin Britten or Iannis Xenakis’s Persepolis. Track 2 is more sparse, and the sounds get stretched and squeezed in ways that make it hard to tell whether the source is human, instrumental or electronic. Completely absorbing. https://www.cafeoto.co.uk/shop/nakul-krishnamurthy-tesserae/ On the subject of India and avant-garde music, Paul Purgas did a fascinating programme for BBC Radio 3, Electronic India, prompted by the discovery of a box of tapes at the National Institute of Design in Ahmedabad.

Maalem Mahmoud Gania – Aicha (Hive Mind Records). Originally released in Morocco in the late 90s on cassette. Mahmoud was a guimbri player and singer. This is nourishing, spiritual music. The album comes with liner notes including lyrics and analysis by Tim Abdellah Fuson of Moroccan Gnawa music and ritual.

Doris Norton – Personal Computer (1984). I wasn’t aware of Doris Norton until someone re-tweeted a link to this album. As a pioneer of computer music, she deserves to be better known. Norton was a singer in Italian prog rock band Jacula in the 70s before her solo work involving the computer in the 80s. She became the first musician endorsed by Apple and later a consultant for IBM. I’d somehow missed the interviews she did for The Wire and Resident Advisor a couple of years ago, coinciding with the vinyl reissue of 3 albums, but I’m happy to have caught up now.

Pantea is an electronic musician from Iran, and Everydaymeal is an audio-collage made from field recordings in and around Edinburgh and Tehran. There’s been quite a lot of this kind of work recently, but this stands out for me as one that’s particularly engaging. I also liked Things (Active Listeners Club), made with more synthetic sounds. Pantea has been helping me learn about Persian music, specifically Arabic Maqam, a system of melodic modes and a form of traditional folk music also shared with Turkish and Azerbaijani cultures. I’d used part of the Maqam system in a sonification of coronoavirus genome data and done some research on it, and so we exchanged music and articles. One reason for this research is that I just like this kind of music and would like to understand/appreciate it better; another is to break free from the Western 12-tone equal-tempered scale system (on that subject, I recommend this article by Khyam Allami). In December Pantea did her first solo live performance on the SWGBBO online platform, a virtual club where you can hang out and chat as a pixel-art avatar. The event also included Kindohm, Parsa & Ramtin Niazi (who started the Active Listeners Club label) and Calum Gunn.

I think it was listening to Music From Mills (get it from UbuWeb) that got me into Maggi Payne. It’s a compilation album from 1986 celebrating the centennial anniversary of the Californa college where Payne was co-director of its Center for Contemporary Music from 1992 to 2018. Dave Burraston used the college’s 1965 Buchla 100 synth, together with his own cellular automata programs, to make his MILLZ MEDZ album. I soon realised that, like Maryanne Amacher, Maggi Payne is a creator of some spectacular sounds. This year Aguirre Records reissued Ahh-Ahh (2012), and it’s become one of my favourite albums. Joshua Minsoo Kim interviewed Maggi Payne for Tone Glow, where you can also hear and download a new mix, ‘Immersion, Bay Area Soundscape’.

PBTHAL makes high-quality digital rips of records that you’re unlikely to find, recorded on equipment that you could never afford. Previously available only through file-sharing, in January the PBTHAL ARCHIVES started as a blog that collected all the old rips together, provided download links, and added new ones frequently. In November it was taken down, but it now seems to have appeared again here (you just have to email for the links).

One of the genres I returned to this year that helped keep me going was jungle. I dug out my old vinyl – Photek 12″s and the Metalheadz compilation Platinum Breakz, and I listened to some old cassette mixes from Yaman Studios by Peshay, downloaded from Hardscore.com. I also watched some old documentaries, like Jungle Fever (1994) which was part of the All Black series on BBC2, and a Dutch programme from 1996 featuring Squarepusher, Photek and Source Direct.

Pulsar synthesis is a method for making sounds involving the generation of a stream of (usually very short) pulses and was originally designed as a computer program by Curtis Roads and Alberto de Campo in 1997. Its roots lie in the quantum theory of sound proposed by Dennis Gabor (1947), in which sound is composed of ‘acoustical quanta‘, and it is related to granular synthesis – a method first realized by Iannis Xenakis (1959). Whilst possible of producing a wide variety of sounds, the main characteristic of pulsar synthesis is typically a sharp, thin, piercing kind of sound that transforms unnaturally quickly. A bit like a digital version of chewed-up tape. Music made with these tortured synthetic screeches has provided a suitable soundtrack for this shitty year, and many of these albums have been made with one particular bit of new software: the New Pulsar Generator (nuPg) created by Marcin Pietruszewski, who was also part of $ pwgen 20, a collaborative group and label set up by Victor Moragues and RM Francis based on pulsar synthesis, which I’ve been a small part of since Marcin helped me to get nuPg running on Windows. Marcin Pietruszewski’s The New Pulsar Generator Recordings Volume 1 is an organized collection of demonstrations of what nuPg can do and a document of Marcin’s practice-based research. The CD came with a booklet reproducing Curtis Roads chapter on pulsar synthesis, beautifully designed by Joe Gilmore. Marcin also wrote about Auditory Sieve (ETAT) in a PDF that comes with the download. Also, Presto!? Records re-released Point Line Cloud by Curtis Roads.

Propagandhi – Victory Lap (2017). I saw Propagandhi when they last played at Rock City, Nottingham in 2013, after they’d recruited a second guitarist that added a more melodic element to their hard sound, making it even more complex, but I hadn’t kept up to date since then. I caught up this year, and Victory Lap made an appropriate soundtrack to 2020.

Lucy Railton made some really good things. First there was Forma, a split release with Max Eilbacher on GRM’s Portrait series. Louange à l’éternité de Jésus was a cello and organ piece by Messiaen whose proceeds went to charity. My favourite is S-Bahn (Boomkat Editions – Documenting Sound), made with recordings of the light rail transit system in Berlin.

C. Reider‘s Radiodrones is made from recordings of AM and shortwave radio. These processed recordings sound like the retro-futurism of Edward Artemiev’s score for Tarkovsky’s Solaris.

claire rousay – Both. Inaudible for the first minute and a half, the first of the two tracks slowly reveals the quiet noise of a library. Subtly manipulated, the noise builds and reveals the echoes of distant voices, reverberated electronic bleeps and mechanical clanks, and a low muffled drone of traffic. In contrast, the other track starts suddenly, a close-up of crackling noise rather than a distant perspective, exterior rather than interior.

SDEM – ZNS. A collection of beat-based tracks made between 2004 and 2019.

Shedding made two albums of generative music based on flocking algorithms related to the original Boids program by Craig Reynolds. Flocking KF Variations was released on FLUF at the start of the year, and Flocking 19 came out via SUPERPANG in November.

Tone Glow has provided some of the most interesting interviews with musicians and the most useful reviews and recommendations. The epic and meandering interview with Jim O’Rourke is a particular highlight. https://toneglow.substack.com/

Rian Treanor not only made some great music, File Under UK Metaplasm (Planet Mu), but as a result of lockdown has been working on projects in collaboration with Mark Fell aimed at building communities and improving access to music-making. They developed networked systems that allow them to operate instruments remotely and allow members of the public to connect and make music together. One project involved elderly residents of a care home in Paris, others were arranged for school kids, including one in Bratislava and an online performance for the No Bounds Festival by Rian and two children. I attended Mark Fell’s online masterclass, part of a series on algorithmic music which also included one by CNDSD on TidalCycles. Ostensibly on the subject of Max/MSP, Fell’s class wasn’t actually very useful for learning the program but he showed and explained some of the systems he’s developed for various projects, like the early SND albums. It was a bit like a condensed and interactive version of his PhD thesis. I also really enjoyed his two collaborative albums with Will Guthrie, Infoldings and Diffractions. Bits of field recordings included among the mostly percussive sounds in ‘Infoldings 1’ really add to the disorientating Moire effect of the polyrhythms.

Like most social media, Twitter undoubtedly has its faults, yet despite having a negative impact on mental health it’s been a lifeline during isolation. It doesn’t happen often, but receiving some nice feedback on my music – whether from artists whose work I admire or from complete strangers – means more than any sales numbers or earnings, and so I’ve tried to do more of that myself. Slack and Lurk groups have offered a similar sense of community with less of the downsides, having a more limited social circle and more specific areas of interest. So if you’re reading this and we know each other online, ‘hello!’ and thank you (not that this blog is any more real than those virtual networks, but, all the same, thanks).

Valhalla make some really good audio effect plugins. In June they released a new one, Valhalla Supermassive, for free. I’ve used Valhalla Room reverb for a while, and it’s great. Whereas Room is modelled on real spaces and natural effects, Supermassive allows you to explore a possibility space of artificial effects unconstrained by physical models. It’s based on feedback delay networks, a type of artificial reverb, and it makes complex delay and reverb effects as well as flanging and chorus. In addition to the usual delay time and feedback controls, ‘mode’ sets the algorithm that changes the overall character, ‘warp’ varies individual delay times, and ‘density’ controls how much the echoes mix together. Get it here.

Ricardo Villalobos & Oren Ambarchi – Hubris Variation Parts 2 & 3. Two remixes of tracks from Ambarchi’s album Hubris (2016). This has been one of my most-frequently played albums when needing something less harsh or challenging. That’s not to say it’s bland; this is a complex remix of the original guitar, drum and synth sounds overlaid in multiple rhythms. The remixing increases the amount of variation in Hubris, resulting in something that’s constantly interesting as well as danceable.

The raised profile of Black Lives Matter that followed the protests for Breonna Taylor and George Floyd also brought about the dissemination of resources to learn about black history and acknowledge its cultural contributions. The Dweller Forever library is one such repository of writing from a black perspective focusing on electronic music, organized into ‘reading’ and ‘audio/visual’ resources. There’s a lot of good stuff to read, watch and listen to, like this poignant interview with Drexciya from 2002 recorded just a short time before James Stinson’s death. I learned about Underground Resistance, the collective led by Mike Banks, Robert Hood and Jeff Mills. I was more familiar with their individual work than with the collective, and hadn’t previously appreciated UR’s influence or understood their political approach to art and business.

Tatsuhisa Yamamoto – mipyokopyoko / mupyokopyoko. Yamamoto, a drummer who has worked with Jim O’Rourke, Eiko Ishibashi, Keijo Heino and Oren Ambarchi, released 10 albums this year through Bandcamp. I bought 5 of them, and they’re all very good.

ZZ Top – Eliminator (1983). My mum bought this album for the family when it was released, and I’ve still got that copy of it now. An album I hadn’t listened to for years, dismissed for some reason. On listening again, side A is pretty much perfect, and side B is average. ZZ Top are great when they’re raucous and fast, but equally great when grooving slowly and precisely, like ‘El Diablo’ from the Tejas album (the drumming on that track is phenomenal) and also like this:

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My latest music is another sonification of the coronavirus genome sequence. SARS-CoV-2_LR757995_1c is released via Hard Return, a new label run by Jack Chuter of ATTN:Magazine that specializes in “extremely repetitive/persistent music”. It’s a single track just over 40 minutes long, made of 3 parts: synth, drums and bass. The bass part is based on the first 1-bar segment of the genome sequence and repeats throughout. It provides a regular pattern in contrast to the non-repeating synth and drum parts. The 4 amino acid bases that make up the genetic sequence (a, t, g and c) are mapped to 4 different notes/drums. The notes and drum sounds are linked, so the same note always plays with the same drum sound, e.g. the lowest note always coincides with the kick drum and the next-highest note always coincides with the snare. [Even though I know it’s like this, it doesn’t always obviously sound like it. At least, that’s my experience of it. I’d be interested to hear if your experience is similar or different.]

The notes are based on Jins Saba, a fragment of an Arabic scale/mode called Maqam Saba. In Western tuning, Jins Saba approximately corresponds with 4 consecutive chromatic notes, each 1 semitone apart. But Maqam music uses microtonal rather than equal-tempered tuning systems, so the intervals in Jins Saba are closer to 3/4, 3/4 and 1/2. I used equal tempered tuning but modulated the pitch of the synth. In Maqam music, different scales/modes are associated with different moods. In performance, a scale is selected and musical patterns are built up through improvisation with the fragments (called ‘ajnas’, the plural of ‘jins’) that make up the scale. Jins Saba is the first thing you hear in this video – it’s the lower part of the Maqam Saba scale:

Arabic Maqam is more than just a scale; it’s “a system of scales, habitual melodic phrases, modulation possibilities, ornamentation norms, and aesthetic conventions” (https://www.maqamworld.com/en/maqam.php). I’m learning more about Maqam and Persian music, and I’m getting more data on the coronavirus genome, including data on the genes and proteins encoded by the genome sequence. I hope to use this enriched dataset as the basis for programming timing patterns and chord changes based on the Maqam method.

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I’ve got some more new music out on the label Superpang. It’s a sonification of the coronavirus genome data played with Razor VSTi synth, arranged into a kind of electro beat. The genome data is a list of 4 letters – a, c, g and t – representing the amino acid bases: adenine, cytosine, guanine and thymine. This genome sequence is 29,874 bases long, so there’s quite a lot of data, which makes quite a long track. The COVID-19 coronavirus has a large genome because it’s quite complex in the way it counters the body’s immune system.

The genome data comes from here:

Hunter, C. & Wei, X. (2020). Wuhan seafood market pneumonia virus genome assembly, chromosome: Whole_genome. GenBankwww.ncbi.nlm.nih.gov/nuccore/LR757995.1

And here is a good explanation of what we know about the virus:

Fischetti, M. (2020). Inside the Coronavirus: What scientists know about the inner workings of the pathogen that has infected the world. Scientific American, www.scientificamerican.com/interactive/inside-the-coronavirus/

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Liminal Kicks

Liminal Kicks is my latest album, released on the new label Superpang based in Rome, Italy, with cover art designed by Joe Gilmore. It’s a collection of tracks made with drum synths and saturation. I used Mathematica to generate MIDI files with up to one million notes, where the timing between notes was programmed to change exponentially, with the exponent set to the Golden ratio (1.618 or 0.618). ‘Liminal’ derives from the ancient Greek limen (λιμήν), meaning ‘threshold’ or ‘doorway’.

In physiology, psychology, or psychophysics, a limen or a liminal point is a sensory threshold of a physiological or psychological response. It is the boundary of perception. (Wikipedia)

Each of these tracks crosses this perceptual threshold. As the drums increase or decrease in tempo and cross the threshold, our perception of it changes between rhythm and pitch. At lower speeds, we hear separate events as increasing/decreasing rhythm, but beyond the threshold we perceive a note or frequency, increasing/decreasing in pitch.

Rather than playing around that threshold, these tracks go well beyond it, exploring what happens when the tempo is very high. As the sounds speed up or slow down, there is often a cyclic or fractal pattern in the frequency shaping of the sounds. This is probably due to a kind of Moiré or wagon wheel effect, caused by the constantly changing difference between the length of the drum sounds and the tempo. You can see an example of the fractal kind of pattern in the spectrogram of track 4, ‘kick2tom1048576′:


The sound is made more complex by a saturation effect, which adds some non-linearity to the equation. Sometimes it also produces an effect like a Shepard or Risset tone, an audio illusion of constantly rising/falling pitch, where it generates tones that are overlapping (in time) and parallel (in frequency). You can hear this most clearly in the ‘snare16384’, and see it in the yellow lines in the image below:


In ‘kick5’, a symmetrical track, you can hear the cyclic patterns in the upper frequencies. In the spectrogram they form similar shapes at different scales. Counter-intuitively, as the duration between notes deceases, the size of the patterns increases, and vice versa. This is probably due to the exponential rate of change, which starts fast and slows down, or vice versa.

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MoCap Fractals

Today I learned that some suits used for motion capture use a pattern that’s a variation of the Sierpinski triangle fractal. I happened to see a tweet from @LASTEXITshirts celebrating the birthday of actor Andy Serkis (56 today), and I recognised the pattern on the suit he’s wearing.

Searching for ‘mocap suit sierpinski’ leads via a post on Reddit, Why do MoCap suits use Sierpinski triangles?, to the patent for the design in 2013 by Lucasfilm. The patent describes it as a ‘scale independent tracking pattern’. Fractals are, by definition, scale-independent, i.e. they look the same at any scale. A fractal pattern is useful for motion capture because whether near or far there are always some visible points to track. It also means that some of the pattern is visible when photographed in motion, when the image is blurred.

The pattern used for the mocap suits is clearly not quite scale-independent, however. It has only 4 levels (there are only 4 different sizes of triangle), so the range of scales is limited, but presumably this is sufficient for the job, given the size of a human body and the scale of the image on screen. Also, the pattern isn’t the same at all levels – only the largest triangles have smaller triangles within them – but it seems that this isn’t a key feature of how it works (my guess is that this particular pattern was designed to be protected by trademark.). Although the patent describes how the pattern is “configured such that a first portion of the pattern is tracked at a first resolution and a second portion of the pattern is tracked at a second resolution”, this doesn’t rely on the differences in the levels of the pattern. It’s the nested structure of the fractal, its self-similarity, that means different levels of the pattern can be tracked for different levels of detail. Triangles are suitable because they have identifiable points that can be tracked by computer vision algorithms, and these trackable points make up the polygon meshes used in 3D graphics.

As the resolution of the actor and the pattern changes, some trackable portions of pattern may become untrackable by the capture device, and some untrackable portions of the pattern may become trackable. When this happens, vertices may be added or removed from the mesh.

Other shapes shapes work too, if arranged in a fractal pattern. The patent also includes another design for a scale independent pattern based on circles. Like the triangular pattern, the idea is that more shapes can be tracked with greater resolution. By chance, the low resolution of the image in the patent illustrates this feature quite well.


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20×20 – Processed Field Recordings

Processed Field Recordings is my new album out on 20×20, a project and label run by Neil Stringfellow. I met Neil in 2015 on a course about field recording tutored by Chris Watson and Jez riley French, and we’ve both participated in the Disquiet Junto. Under the name Audio Obscura, his work includes Gathering Silence, an album based on recordings in empty old churches in rural Norfolk, and an interpretation of George Orwell’s Nineteen Eighty Four. 20×20 is a project involving 20 artists each making an album of 20 tracks that are 20 seconds long. The first album was released on 20th January 2020, with subsequent releases scheduled every 20 days. This is the 5th in the series, following albums by haLF unusuaL, Daniel Diaz, Tay_ploops and Minimal_Drone*GRL. 

The album and track titles are plainly descriptive. It’s based on recordings I’ve made over the past 10 years in different places: Nottingham city and riverside, a village in Rutland, a smallholding in rural Norfolk, and national parks in Derbyshire and North Yorkshire. The sounds are processed with various effects and some have synthesized sounds added. In all cases, some parameters of the effect or synth are controlled by aspects of the source sound, e.g. volume, pitch and timing. To varying degrees, the processing highlights and obscures elements of the sounds. This is my second album based on field recording. The first was Hyperchaos Volume 1, a collaboration with 23 artists, where the tracks were limited to a maximum of 1 second each. 

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6-Colour Block Cellular Automata

Here are some results of recent tests with 6-colour cellular automata. These are 6-state relations of the simple 2-state block cellular automaton that I use a lot, rule 39 in Wolfram’s notation which translates the output states of the rule specification into a decimal number. This rule family uses a 2-cell block, offset by one cell each generation, so it tiles in a brickwork pattern. Rule 39 of the 2-state CA translates to: “if both cells are in the same state, change state on the next step; if cells are in different states, remain in the same state.” In the program run in Mathematica, this is applied as a set of transformation rules operating on lists of numbers. In full, these are: {0,0}→{1,1}; {0,1}→{0,1}; {1,0}→{1,0}; {1,1}→{0,0}. The rule 39 specification is visualised below. The top half of each part represents the current states of the two cells in a block; the bottom half represents the states of those cells in the next generation.

The rule specification has one part for each possible configuration of states in a block. The number of different possible configurations with a block size n and with k colours is equal to k^n, so a k=2, n=2 CA such as rule 39 has 2^2 = 4 parts. A 6-colour CA rule has 6^2 = 36 parts. The number of different rules is equal to k^(n×(k^n)). With 2 colours, there are 256 possible rules. With 6 colours, there are 106387358923716524807713475752456393740167855629859291136. This is too many to explore exhaustively, so I explored a subset by using constraints. The constraints were to incorporate the k=2 rule 39 pattern within the k=6 rule with at least one pair of colours, and to generally conserve the colours by limiting the rule specifications to simple transformations. Rule 39 conserves the total number of different colours and is reversible, which means that any evolved state can be run backwards, by applying the rules in reverse, and it will return to its initial conditions. In general, a block CA is reversible if its rule permutes all possible blocks. Due to the constraints, many of these k=6 rules meet this criterion and are therefore reversible. This is rule 39 with random initial conditions, 32 cells in size, run for 32 generations:

For the purpose of these tests, the 6 states are represented by the colours red, orange, yellow, green, blue and purple (R,O,Y,G,B,P). The final colours might be different, depending on how printing tests turn out, but will have a similar spread, being equally-spaced on the trichromatic colour wheel. My aim is to find combinations of rules and colours that induce perception of secondary colours through optical mixing.

Below are some results of 6 different rules tested with three sets of initial conditions:

  1. Random choice of all colours (R/O/Y/G/B/P)
  2. Three pairs of complementary colours picked randomly (R/G, O/B, Y/P)
  3. Three pairs of neighbouring colours picked randomly (R/O, Y/G, B/P)

I generated one of each type of initial condition, and used this set of 3 for all rules shown here, to make the differences more visible. The initial condition is the top row, and time runs downwards from the top. Each CA is 240 cells in size, run for 240 generations.

Rule 20774264240371331443939583648662020862331869895110587700

This k=6 rule incorporates 2 instances of the k=2 rule 39 pattern: instead of black and white (B/W), it’s R/O and B/P. You can see these in the top-left and bottom-right corners of the rule specification above. Random initial conditions (top) produces a bit of a jumble, but a pleasing combination of colours. Complementary pairs of colours (middle) makes a nice gradient out of reticulated patterns. Neighbouring colours (bottom) makes a horrible geometric mess.

Rule 20796116639275282756883592732765805970567318290529775700

This rule incorporates 3 of the k2 rule 39 pattern with 3 pairs of neighbouring colours: R/O, Y/G and B/P. The random conditions produce a similar thread-like patterns. The patches of colour in the other two blend and interact nicely.

Rule 103541839025819083223383708563702745805808655480680346680

This rule also incorporates 3 of the k2 rule 39 pattern, with different pairs of colours: R/P, O/B, Y/G. Randomness makes mostly vertical structures jostling with each other. In the structured initial conditions, the rule makes for clear areas with rule 39 behaviour that are gradually encroached by tendrils from the neighbouring areas.

Rule 62556620991588118164093337622114268271511526829240714310

This rule incorporates 3 of the k2 rule 39 pattern, with pairs of complementary colours: R/G, O/B, Y/P. In this rule specification, if the colours aren’t one of these pairs then instead of behaving like rule 39, each cell takes on the state of its neighbour, so the colours swap places. The images below are different to the previous ones because the random initial condition produces the most orderly image, comprising vertical repeating patterns. This example is the best of the vertical type patterns yet. In contrast, the other two images are more chaotic than those in the rules shown above.

Rule 62312062993845184628174649112617059049519000489975636340

This rule is quite similar to the previous one but with only 2 rule 39 pairs(R/G, Y/B). I like the squiggly patterns produced by random initial conditions.

Rule 62556620991588118164089965300297552193934650966268789830

Although this rule is very similar to the previous one, it is unlike all the others because it doesn’t have the property of permuting all possible configurations. Two configurations instead of the usual one lead to a configuration of two yellow cells (YY): BB and PP. With all the other rules so far, if you count the total number of cells of each colour in the output parts of the rule specification (the lower half of each part), they are equal, with 12 cells of each colour. In this rule, there are 14 yellow and 10 orange, plus 12 of every other colour. For this reason, it is probably not reversible. It makes some lovely patterns.

Rule 20774264240899287841879128096849235332307474604780057880

This rule differs from all the others because it doesn’t incorporate the rule 39 pattern. In this rule, colours rotate. Whenever a block has 2 cells of the same colour, the colour changes to the next along in the spectral sequence (rainbow order). This property seems to make a mess of any structure in the initial conditions. Interesting to try the rule, but uninteresting results.

Rule 62556585801747746489648698620876988974236430593535788615

What’s different about this – easily visible in the rule spec – is that some same-colour blocks stay as they are (O,Y,B,P). Only R and G are like rule 39. Like most of the other rules, it conserves the colours and is reversible. Not the most interesting results, because this rule doesn’t mix things up as much as the others.

Given that most of these rules conserve the total number of different colours in the initial conditions, it’s surprising how much they differ in terms of overall hue. With the right set of colours, these images can produce the effect of seeing colours that aren’t there, through a combination of optical mixing and colour juxtaposition. This visual effect was explored by Sydney Harry, whose paintings I’ve seen at the colour museum in Bradford. I’d like to see if the effect can work with these CA patterns in print instead of on screen, so I’ll be doing some print tests soon. It would be interesting to see what they look like in large scale – wall-sized, where they can be viewed from near and far.

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Frequency Domain Filtering

On r/puredata Acreil posted this video of generative music made with a pure data patch. It shows a scrolling stereo spectrogram of the music, with wavy lines that represent slices of filtered noise where the filter is always changing. Frequency domain filtering works by applying the Fourier transform to the input signal, resulting in a frequency spectrum which you cut or boost in places, then transform again back into the processed signal. Acreil did a post about this with another video that explains how it works and a link to download the pure data patch. He explains that “frequency domain filtering is nice because what would be a convolution in the time domain becomes a multiplication in the frequency domain.” This kind of processing can make the kind of shapes in a spectrogram that you don’t normally see, because it can make the kind of sounds that you don’t normally hear. The only other thing I know of that looks and sounds similar is the end of the track ‘∆Mᵢ⁻¹=−α ∑ Dᵢ[η][ ∑ Fjᵢ[η−1]+Fextᵢ [η⁻¹]]’ (also known as ‘equation’) from the Windowlicker EP by Aphex Twin. This is the track with the face encoded at the end. The bit that looks like frequency domain filtering is the patch of squiggly lines on the left.

Here’s a close-up on that bit. The face has a different texture – lower resolution, made of lines, whereas these squiggles are smoother, which suggests different techniques were used to make them. But both processes, frequency domain filtering and synthesis from images, involve the Fourier transform. So does the spectrogram. This video of a visual introduction to the Fourier transform by 3Blue1Brown helped me understand what it does.

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