Disquiet Junto Project 0410: Op Audio

Disquiet Junto Project 0410: Op Audio
The Assignment: What does the sonic equivalent of Op Art sound like?

Thanks to Nate Trier for having suggested a “Shepard tone Junto,” which led to this week’s project.

Step 1: If you aren’t familiar with the concept of Op Art, read up. It employs optical illusions as raw material for artistic expression.

Step 2: Think about what the sonic equivalent of Op Art would be. For example, consider the Shepard tone (the illusion of continually rising or descending pitch).

Step 3. Record a piece of Op Audio resulting from your thinking in Step 2.

Seven More Important Steps When Your Track Is Done:

Step 1: Include “disquiet0410” (no spaces or quotation marks) in the name of your track.

Step 2: If your audio-hosting platform allows for tags, be sure to also include the project tag “disquiet0410” (no spaces or quotation marks). If you’re posting on SoundCloud in particular, this is essential to subsequent location of tracks for the creation of a project playlist.

Step 3: Upload your track. It is helpful but not essential that you use SoundCloud to host your track.

Step 4: Post your track in the following discussion thread at llllllll.co:


Step 5: Annotate your track with a brief explanation of your approach and process.

Step 6: If posting on social media, please consider using the hashtag #disquietjunto so fellow participants are more likely to locate your communication.

Step 7: Then listen to and comment on tracks uploaded by your fellow Disquiet Junto participants.

Additional Details:

Deadline: This project’s deadline is Monday, November 11, 2019, at 11:59pm (that is, just before midnight) wherever you are. It was posted on Thursday, November 7, 2019.

Length: The length is up to you.

Title/Tag: When posting your track, please include “disquiet0410” in the title of the track, and where applicable (on SoundCloud, for example) as a tag.

Upload: When participating in this project, post one finished track with the project tag, and be sure to include a description of your process in planning, composing, and recording it. This description is an essential element of the communicative process inherent in the Disquiet Junto. Photos, video, and lists of equipment are always appreciated.

Download: Consider setting your track as downloadable and allowing for attributed remixing (i.e., a Creative Commons license permitting non-commercial sharing with attribution, allowing for derivatives).

For context, when posting the track online, please be sure to include this following information:

More on this 410th weekly Disquiet Junto project — Op Audio / The Assignment: What does the sonic equivalent of Op Art sound like? — at:


Thanks to Nate Trier for having suggested a “Shepard tone Junto,” which led to this week’s project.

More on the Disquiet Junto at:


Subscribe to project announcements here:


Project discussion takes place on llllllll.co:


There’s also a Disquiet Junto Slack. Send your email address to twitter.com/disquiet for Slack inclusion.

The image associated with this project is from the Wikipedia entry on the logarithmic spiral:



The project is now live.

Excellent. Thanks for this.

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OK, so back in 2001 I went to the Ontario Science Centre. I have this snippet of memory about an illusion zone that included an auditory illusion - one voice repeating “stress” (or dress? or tress?). And I just read about something called the Speech-to-Song Illusion (https://en.wikipedia.org/wiki/Auditory_illusion) which also seems amazing.

This uses online services to make a text-to-speech-to-song (plus some Reaper synths and a ring modulator for kicks). Quotes from Darwin and a report I found about hair care products (I think).


Ah my- I was happy to see this idea. I revisited a gigantic composition that I’ve been working on getting a recording of for the better part of a year. It’s full of these Reichian process-music style drones that change and evolve. I spent about an hour combing through, and this was the isolated instrument that seemed most in line with the project. It’s simple- just a single unprocessed live take of a cheap scratch and dent Squier Baritone Jazzmaster bowed with a violin bow, but it is the best expression I have of this idea.


So this is from 2012. When listening to the original track, you all know it, I suddenly realized that the chorus is repeating its first line, only a semitone up in the repetition. What would happen if I sample that and add more repetitions, each one a semitone up? And then layer it in a way that it works like a never ending shepard tone? Would the euphoria, that this chorus injects in everyone, would that euphoria also rise and rise and rise?



One arpeggio in “Trompe-l’œil” (minor? major?) performed on guitars (electric? acoustic?)

added some treated orchestral samples.
Guitars (3 instruments, 8 tracks) performed by DD Friday November 8th.
Photo by DD (Oslo, Norway, 2018)


In this experiment, I tried to demonstrate a Moire effect in sound. The Moire effect is typically associated with 2 or more overlapping patterns which are similar so that when moved across each other, they produce recurring patterns different from any of the original patterns. For the Moire effect in sound, I used Supercollider to play a progression of 4 chords comprised of 4, 5 or 6 notes which are “strummed”, the time between notes within the chords is the same throughout the piece. I programmed the algorithm to play all 4 chords in a repeated cycle - they start out as 4 almost completely overlapping “strums” and then slowly, with each loop the chords are dragged apart from each other by increasing the interval between the start of each chord. As this occurs, the chords slowly become offset from each other allowing individual notes from the different chords to fill in the gaps, like overlapping combs. This creates new patterns as the chords progressively become separated from one another until the individual chords are completely resolved. I programmed the notes to sound like a classical nylon guitar.


I first composed a small symphonic riff - and then cut everything up in pieces, like seeing a picture through a grid or a comb, to see if the idea of the original would “peek through” - or maybe even change character. I think it changed quite a bit; some parts gained importance, other disappeared and some got almost too intrusive. But I actually like it better like this… :slight_smile:


Using an image Jelie sent me from a mountain music class she was doing. I loaded it into Photosounder inverted it to get a more traditional OP black and white image. I then used the black and white tools to draw trees using the tools.
inverted trees.

I then took the inverted image’s sound, duplicated and reversed it. I then took the “drawn” inverted images sound, duplicated and reversed it. Using these 4 sounds I grouped them in Abelton to a looper and EQ.

I then dialed in some drums on the Roland DJ 808 drum sequencer apx 71 bpm for the 606, 707,808, 909 drum banks. I then used the MIDI fighter routed to a drum kit with a looper to capture a phrase that I then folded into the group Loop chain.

I really enjoyed making this one and can’t wait to see what everyone does!


The playlist is now rolling:

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Another really thought/imagination provoking prompt. Thanks to Marc and Nate Trier for the initiative!

Immediately I thought of Bridget Riley’s work, which I’ve always loved; especially her intricate colour works, which started in the 80s/90s onwards with pieces like Achæan (1981) and Nataraja (1993). I’ve always appreciated the considered selection of colour palette along with the rigid repetition of lines or oblique shapes. Throughout her career, Riley has meticulously studied the use of colour in paintings across history, as well as colour’s application in cultures around the world. Her late work - from the 2000’s onwards introduced elements of curvature and fluidity, and the semblance of repetition and repeated patterns became less apparent/distinct.

Achæan (1981)

Nataraja (1993)

Blue and Pink (2001)

In a sonic/musical sense, her work from these respective periods suggests a strong correlation to movement/momentum, pulses, repeated motifs, polyrhythm, phase relation and colouration of tone, etc.

I thought it might be interesting to reference this late development in Riley’s work: from the rigid forms and colour palette of Achæan (1981) and Nataraja (1993)through to her more recent works, which pull away from repetition, yet eschew the broad colour palette to only a couple of colours (such as Blue and Pink, 2001).
My piece is sort of caught between works such as Nataraja and Blue and Pink: starting with repetitions and degrees of colouration, before being gradually swept away in a homogony of sorts.

I used a customised synth patch on my microkorg and routed the output to three effects pedals (an Ooh Wah, DD7 looper and Earthquaker Transmisser).

The Ooh Wah is a rare bespoke pedal which I’m borrowing from a friend at the moment. It’s essentially a series of bandpass filters combined with a sequencer. It adds a nice warbling effect to the synth, whilst pressing out some interesting harmonic characteristics.

The DD7 is, well…a DD7. I’m using it to capture sections of my playing and repeat infinitum, whilst overdubbing additional sections as the piece goes on.

Lastly, the Transmisser is a glorified modulated reverb, which I’ve employed towards the end of the piece to essentially ‘blend’ the colours into a homogenous impression.

It’s longer than my usual submissions, since I felt a length of at least four minutes was the only way I could get this idea across.


Nice contribution, Tristan. Here’s a couple of articles by Neil Dodgson, analysing Riley’s work.

‘Regularity and randomness in Bridget Riley’s early Op art’ http://neildodgson.com/pubs/cae08.pdf

Mathematical characterisation of Bridget Riley’s stripe paintings’


Oh that’s excellent, @guy. Thanks heaps for posting this - fascinating.


Having known a little about the mathematical structure of Riley’s paintings, I must admit that I was a bit torn between whether to go fo an impressionistic/intuitive (this version) or a more stochastic/algorithmic approach (such as using Max.) I’ve really been dying to use the Ooh Wah pedal at some point too! I was kicking myself a couple of months ago that I didn’t utilise it for the previous Filterbox assignment (0403.)

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I created two mirror image-struck-bar unit generators (with rotating presets), opposite rotating pans, opposite LFO’d pitch, opposite LFOd echo intensity–the idea is to create a sense of spatial disorientation. Code is here:


For this, I played around with two audio illusions - the shepard tone and panning effects to create the feeling of motion. To intensify the shepard tone experience, I reversed two of the tracks.

The name references the halocline - a vertical zone in the oceanic water column in which salinity changes rapidly with depth, located below the well-mixed, uniformly saline surface water layer. For divers, this can cause disorientation due to loss of visibility.

Best listened with headphones :slight_smile: