glitch « Coding, Sounds and Colors | A blog about algorithmic experiments in music and visual art. Sort of.

A sequenced fx machine

posted by me on 2014.01.19, under Supercollider

19:

Ever wondered how to make a sequenced fx machine, where the effects cut each other out (like dbGlitch, say)? Here’s a very simple example

SynthDef(\fx, {arg out = 0, in, trig = 0, lag = 0.1, grid = 1/2, bit = 7, sample = 5000;
var sig, del;
sig = In.ar(in,2)*0.5 + Select.ar(trig, [In.ar(in, 2)*0.5, LocalIn.ar(2), LPF.ar(Decimator.ar(In.ar(in,2)*0.5, sample, bit), 6000)]);
del = DelayL.ar(sig, 1.0, Lag.kr(grid, lag));
LocalOut.ar(HPF.ar(del*(trig.clip(0, 1)), 2000));
Out.ar(out, Pan2.ar(sig[0], TRand.kr(-0.5, 0.5, trig)*trig));
}).add;

which uses the Ugen Select.ar, which functions as a “one-to-many” audio switch*. The delay part works as a simple beat repeater, and the other effect is a bit-crusher. After instantiating an audio bus, you can then delegate the sequencing to a Pmono

~rep = Bus.audio(s, 2);

Pmono(\fx, *[\trig : Pwrand([0, 1, 2], [0.4, 0.3, 0.3], inf),
\grid: Prand([1/2, 1/4, 1/8, 1/16], inf),
\bit: Prand([7, 10, 8, 24], inf),
\sample: Pwhite(1000, 10100, inf),
\lag: Pwhite(0, 0.1, inf),
\in: ~rep,
\dur: 1/8]).play(quant: 4);

Whatever you send to ~rep will be processed by the fx SynthDef (be careful with the order of execution, or use Group to be on the safe side). If you have already SynthDefs for the single effects you would like to use, it is more convenient to send the audio to single busses, and then add a SynthDef at the tail of the synth chain containing a Select.ar Ugen which will choose among the different effects. You will have to run additional Pmonos to control the various parameters, though.
Notice that this approach to sequenced fx machines is quite expensive, since the various effects will run constantly on the server.
Anyway, in this simple case it sounds like

Audio clip: Adobe Flash Player (version 9 or above) is required to play this audio clip. Download the latest version here. You also need to have JavaScript enabled in your browser.

*You can use a similar approach in Max/Msp, Reaktor, etc.

{ no comment } :| { Tags: glitch, supercollider }

Glitch Aesthetics and digital music

posted by me on 2013.03.29, under Supercollider

29:

Here’s a little Supercollider code which tries to emulate the sonorities of artists like Alva Noto, Ryoji Ikeda, etc., with their blend of broken sine waves and percussive tones.

s.boot;

(
SynthDef(\main,{arg out=0, f=50,t_trig=0,p=0,i=0,d=10,l=0.1,a=0.5,n=1;
var fmod=SinOsc.ar(f/60,0,f/60);
var sig=[SinOsc.ar([f,f+600]+fmod,0,[d,0.005]).mean.tanh,HPF.ar(WhiteNoise.ar(1),8000),SinOsc.ar(30,0,1),VarSaw.ar(f/40,mul:d*10000)];
var env=EnvGen.ar(Env([0.0,1.0,0.0],[0.0,l]),gate:t_trig);
Out.ar(out,Pan2.ar(((Select.ar(i,sig)*env).fold(-1,1)*0.7+SinOsc.ar(40,0,0.3))*(1+HPF.ar(WhiteNoise.ar(0.02*n),8000)),p)*a);
}).add;
SynthDef(\hat,{arg out=0, f=50,t_trig=0,p=0,a=1;
var sig=HPF.ar(WhiteNoise.ar(1),6000);
var env=EnvGen.ar(Env([0.0,1.0,0.0],[0.0,0.01]),gate:t_trig);
Out.ar(out,Pan2.ar((sig*env*a),p));
}).add;

y=Pmono(\main,\dur,Pxrand((1/8!8)++(1/4!8)++Pseq([1/16,1/16],Prand([1,2],1)),inf),\trig,1,\p,{rrand(-1,1)},\i,Pwrand([0,1,3,4],[0.946,0.03,0.02,0.004],inf),\d,Pwrand([1,30],[0.98,0.02],inf),\f,Pwrand([35,40,6000,20000],[0.30,0.65,0.03,0.02],inf),\l,{rrand(0.1,0.5)},\n,{[1,2,3,30].wchoose([0.8,0.1,0.05,0.05])});
z=Pmono(\hat,\dur,Pxrand((1/8!8)++(1/4!8)++Pseq([1/32,1/32,1/32,1/32],Prand([1,2],1)),inf),\trig,1,\p,{rrand(-1,1)},\a,0.1);

w=Ppar([y,z],inf).play;

)

s.quit;

Audio clip: Adobe Flash Player (version 9 or above) is required to play this audio clip. Download the latest version here. You also need to have JavaScript enabled in your browser.

The main idea is to produce the percussive elements by a discontinuous volume envelope, so the “clicks” you hear are just the sine waves having a discontinuity. For this reason also I’ve preferred to use a Pmono, rather than a Pbind as the main rythmical sequencer. Also, via the Select UGen, one can obtain abrupt changes in the sound wave, producing again clicks and quirky noises.
The idea of the rythmic part comes from some post on the Supercollider Mailing List (can’t recall which one right now) using duty UGens, though.
Of course, to get what Noto and Ikeda do, it takes a long route: it’s when techniques end, and art begins.
I highly suggest these, if you are curious about this type of stuff