Fellow ChucKists,

Yesterday I wanted to wish Dan a happy birthday on FaceBook, hoping for many more years of fun with strings and code but thought it'd be nicer to write this in ChucK. Then stuff happened and I was too late.

Belated but no less sincere; emulating strings in LiSa... because we can, and because LiSa can (LiSa can actually do anything, she's just modest). We start out with a very literal implementation of Karplus-Strong at concert A4 tuning. Then we start mucking with various parameters in ways that are less traditionally Karplus-Strong for some more interesting tembral effects.

Yours,

Kas.

/*

Do copy, do share.

No warranties, no refunds.

Physical models can (and will!) blow up; please mind your speakers, neighbours and pets.

Remixing and sharing results strongly encouraged (many parameters left....).

Happy belated birthday to Dan!

*/

//the patch (noise or a saw plus a envelope could emulate a bow instead of a pluck)

Impulse i => LiSa l => dac;

//needs to be defined

second => l.duration;

//two voices for averaging

2 => l.maxVoices;

//buffer duration = source of the pitch

second / 440 => dur base_cycle;

//create a looping delay

//looping for both recording and playback is on by default

base_cycle => l.loopEndRec;

l.loopEnd (0, base_cycle);

l.loopEnd (1, base_cycle);

1 => l.record;

//offset the second voice by one sample

//so we average between the current and the last sample value

l.play (0, 1);

l.playPos (1, -1 * samp); //"::" should work here but gives me a error? [BUG]

l.play( 1, 1);

//average between the two values. ratio sets the "filter's" effect.

//make sure the two add up to unity (1.0).

l.voiceGain (0, .5);

l.voiceGain (1, .5);

//feedback sets the tone's decay

.995 => l.feedback;

//off we go!

1 => i.next;

2::second => now;

//tradition ends here.

//fun starts

l.loopEnd (1, base_cycle * .5);

1 => i.next;

2::second => now;

l.loopEnd (1, base_cycle * 2);

1 => i.next;

2::second => now;

l.loopEnd (1, base_cycle * .333333);

1 => i.next;

2::second => now;

l.loopEnd (1, base_cycle * 1.5);

1 => i.next;

2::second => now;