Episode 11: In the Mountains and in the Tombs

A further continuation of the rhythmic idea used in Episodes 7 and 8, this time implemented as a sctweet. mp3 file: In the Mountains and in the Tombs (sctweet 20150210) (3.1 MB) Full supercollider source: play{l=LFSaw;a=Decay.ar(Impulse.ar(1/8),0.2,l.ar(l.kr(2/25,0,88,176)));[16,10,4,3].do({|t|a=CombN.ar(a,6,t/8+[3,4],20,1,a)});a}//#sctweets (138 characters) I managed to create an even shorter tweet, which differs only in the amplitude envelope of the notes. I didn't think it sounded quite as pretty, though: play{l=LFSaw;a=HPF.ar(l.ar(1/8),8,l.ar(l.kr(2/25,0,88,176)));[16,10,4,3].do{|d|a=CombN.ar(a,6,d/8+[3,4],24,1,a)};a}// #sc140 #supercollider The notes of this composition follow a cycle of 25 pitches, taking 3 minutes and 20 seconds to perform a single repeat. Each note is echoed in a complex rhythm, creating the arpeggios you hear. This recording follows one complete cycle of pitches. Here's an expanded version of the tweet that explains what's going on: ( { var pitch=LFSaw.kr(2/25,0,88,176); // the pitch rises from 88Hz to 264Hz (an octave and a fifth) in 12.5 seconds var tone=LFSaw.ar(pitch); // generate a sawtooth wave following the pitch var env=Decay.ar(Impulse.ar(1/8),0.2); // 0.2 second percussive envelope that repeats once every 8 seconds var note=env*tone; /* the original tweet performs the same multiplication in the * mul: parameter of the Decay ugen * * this combination produces the 25 note cycle. The notes * are harmonically related because the pitch rises in a linear * fashion. If the pitch doesn't wrap around before the next note, * it will be 32/25 * 88Hz higher. If it does wrap around, it * will be 18/25 * 88Hz lower. The total set of all notes played * consists of harmonic partials 13-37 of a fundamental frequency * of 7.04 Hz. (41 cents above A-6) */ var delaytimes=[16,10,4,3]; // delaytimes measured in 16th notes at 120bpm var out = note; // chain all the delays: delaytimes.do{|delay| var delayinseconds=delay/8; var stereodelay=[3,4]; // left channel delays an additional 6 beats at 120bpm, // right channel delays an additional 8 beats out=CombN.ar(out,6,delayinseconds+stereodelay,24,1,out); }; // uncomment this line to see what frequencies are being used: // Poll.ar(Impulse.ar(1/8),ZeroCrossing.ar(tone),"freq"); out; }.play ) The multiple long delay times consume quite a bit of memory. To run these in supercollider, you may have to increase the server's memory capacity. This worked for me (run before booting the server): s.options.memSize=(2**15) As usual, the title of this track is chosen from a randomly selected Bible passage. By total coincidence, the song Legion by Severed Heads refers to the same passage.