Adelaide Festival.

(DURHAM) I submitted a soundtrack piece from a couple of years ago, The Method, to the 2014 Adelaide Festival for inclusion in their fantastic “Sound Introversion” web radio stream. If you couldn’t make it down under for the festival, why not check out the global mix of new ambient, drone, minimal, and low-volume electronica here.

In other news, I’ve built a little calculator in SuperCollider which figures out the notated beat divisions required for 2-limb polyrhythms. You can simply substitute your own integers for limb1 and limb2, and SC will output the various possible formats with the total duration units per format.

// polyrhythm calculator based on a formula from Andrew Mead:

var limb1 = 21;      // add your own integers for limb1 and limb2
var limb2 = 25;

var limb1factors = limb1.factors;
var limb2factors = limb2.factors;
var formatDurations;

if(limb1factors.size == 1, { limb1factors.add(1) });
if(limb2factors.size == 1, { limb2factors.add(1) });

if(limb1factors.size > 2, { t = limb1factors[0]*limb1factors[1];
	limb1factors.removeAt(0); limb1factors.removeAt(0); limb1factors.add(t);

if(limb2factors.size > 2, { u = limb2factors[0]*limb2factors[1];
	limb2factors.removeAt(0); limb2factors.removeAt(0); limb2factors.add(u);

a = limb1factors[0];
b = limb1factors[1];

x = limb2factors[0];
y = limb2factors[1];

formatDurations = [[y/b, a/x], [x/b, a/y], [x/a, b/y], [y/a, b/x]];

("Format A –  "+limb1+":"+y+"/"+b+"  "+limb2+":"+a+"/"+x+"  Number of duration units: "+((y/b)*limb1)).postln;
("Format B –  "+limb1+":"+x+"/"+b+"  "+limb2+":"+a+"/"+y+"  Number of duration units: "+((x/b)*limb1)).postln;
("Format C –  "+limb1+":"+x+"/"+a+"  "+limb2+":"+b+"/"+y+"  Number of duration units: "+((x/a)*limb1)).postln;
("Format D –  "+limb1+":"+y+"/"+a+"  "+limb2+":"+b+"/"+x+"  Number of duration units: "+((y/a)*limb1)).postln;
formatDurations.round(0.001).postln;   // change the amount of rounding for more/less precision

This allows you to quickly check if certain integer combinations might work well in terms of the required beat divisions for each limb, although at the moment the code only works for integers with 3 or fewer prime factors.

I’ll wrap up today’s post with another game I played as black against Deep HIARCS 14 (computer playing at 1700 Elo) several weeks ago. My endgame technique is getting better!

One response

  1. Matthew Marsolek of the Drum Brothers in Missoula would be all over this. He used to figure out these things by hand and was up to 7 simultaneous rhythms using various limbs including his head, and breath. Did strange, meditative things to his head.

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