Category Archives: 2021

Shorts #41: Catalyst

Shorts #41: Catalyst. Commissioned and titled by Andy Bannister

This piece was commissioned and titled by Andy Bannister.

Explaining why he picked this title, he said, “My thought process for this, is that the first half sounds like a catalyst for a reaction towards the latter half which could also be interpreted the sound of a substance or object changing state, like liquid to gas etc.”

The time elapsed between the original commission and this post is a lot longer than usual and I can’t remember how the piece was made, but according to my filing system, it was made using chaos synthesis on a Eurorack. This is a type of frequency modulation where oscillator A modulates oscillator B, which modulates oscillator C which modulates oscillator A. This is an exciting system because the feedback makes it chaotic.



Glass – for Irene’s birthday

This piece was composed using SuperCollider and a synthesiser for Irene’s birthday. It was presented as a part of an installation at the Rupture Gaming Festival in Kent.

The source material is recorded with an analogue modular synthesiser. The SuperCollider program takes that material and granulates it, dramatically changing the playback speed.


Sawtooth Minimalism

Sawtooth Minimalism

My colleague, Jackie Walduck, was showing students how to create phase music by putting loops out of synch in a DAW. Then I went home from teaching and created a PD patch to play low-pass filtered sawtooth waves, as an example for a different class. I got curious how much easier it would be in SuperCollider and created a tiny program that did the same thing and set it going at the same time. Then I started it again. The phasing was fixed, but it called to mind the shifting relationships of earlier that day.

This version is only SuperCollider, but it uses a non band limitted sawtooth to mimic phasor~ in PD. This version is 7 minutes long, but the proper version should be about 3 hours. I get lost in the phasing and feel relaxed.

I’ve attached the code below. If you want to to last longer, look for the number 340 – that’s 5’40” in seconds. Make it as long as you’d like.

	var scale, dur, pb, steps=16, loops = 4, loop_calc, env_dur, db = -14, fade_in=40, decay = 20;

	loop_calc = {|note_dur, section_dur|
		var loop_dur, total_dur;

		loop_dur = note_dur * steps * loops;
		total_dur = loop_dur * (section_dur/loop_dur).ceil;

	SynthDef(\saw, {|out=0, freq, amp, dur, pan|
		var saw, env, lop, pan2;
		saw =;
		lop =, freq*4);
		env =, doneAction:2);
		pan2 =, pan, env);, pan2 * amp);

	//s.prepareForRecord("/home/celesteh/Documents/Pieces/SawtoothMinimalism/take-" ++ Date.getDate.rawSeconds ++".wav" , 2);



	dur = 60 / 250; // 250 BPM

	env_dur = loop_calc.(dur, 340) - (fade_in+ decay);

	scale = Scale.minorPentatonic(Tuning.choose(5));

	pb = {|limit = 7|
			\instrument, \saw,
			\db, db,
			\dur, dur,
			\scale, scale,
			\degree, Prout({
				var loop;{
					loop = steps.collect({ /*scale.degrees[5.rand]*/ limit.rand });
					loop = loop.scramble;{{|step|
			//\midinote, Pkey(\add) + offset,
			\out, 0


		Pbindf(pb.value, \octave, 4, \pan, 0, \continue, Pn(1,loops*steps)),
			0, Pseq([
				Pbindf(pb.value, \octave, 4, \pan, -75, \continue, Pn(1, loops*steps*4)),
				Pbindf(pb.value(5), \octave, [4, 5], \pan, -1, \db, Penv([db, db-2, db, db], [fade_in,decay, env_dur])),
				Pbindf(pb.value, \octave, 4, \pan, -0.88, \db, Pn(db+1, 1), \degree, [0, 2], \dur, dur*8)
			] ),
			0.0008.rrand(dur/10), Pseq([
				Pbindf(pb.value, \octave, 5, \pan, 75, \continue, Pn(1, loops*steps*4)),
					0, Pseq([Pbindf(pb.(5), \octave, [4,5], \pan, 1, \db, Penv([db, db-2, db, db], [fade_in,decay, env_dur])),
						Pbindf(pb.value, \octave, 4, \pan, 0.88, \db, Pn(db+1, 1), \degree, [1, 4], \dur, dur*8)]),
					(dur * 0.3).rrand(dur*0.7), Pseq([ Pbindf(pb.value,
						\octave, 5,
						\pan, Pwhite(-0.1, 0.1),
						\dur, Pwhite((dur / -700), (dur/700)) + dur,
						\db, Penv([-60, db+1, db, db], [fade_in, decay, env_dur])),
					Pbindf(pb.value, \octave, 5, \pan, 0, \db, Pn(db+1, 1), \degree, [0, 3, 5], \dur, dur*8)


			\dur, dur,
			\freq, Prout({