Just intonation MIDI keyboard with SuperCollider

gistfile1.scd

/**
 * Just intonation MIDI keyboard with SuperCollider
 */

MIDIIn.connect;
s.boot;

(
SynthDef("umbSimpleFM",{
	arg freq=440, gate=1, amp=1, pan=0;
	var m_amp, mod, car;
	m_amp = 100;
	mod = SinOsc.ar(freq*2, 0, m_amp);
	car = SinOsc.ar(freq + mod, 0, amp);
	car = EnvGen.kr(Env.adsr(0.01,0.3,0.5,1,0.6,-4),gate,doneAction: 2) * car;
	Out.ar(0, Pan2.ar(car,pan));
}).add;
)

(
var keys, scale;
keys = Array.newClear(128);
scale = Scale.chromatic.postln;
scale.tuning_(\just); // Just intonation
//scale.tuning_(\et12); // Twelve-tone equal temperament
//scale.tuning_(\mean4); // Meantone, 1/4 Syntonic Comma
//scale.tuning_(\pythagorean); // Pythagorean

~noteOnFunc = {arg src, chan, num, vel;
	var node, freq;
	node = keys.at(num);
	if (node.notNil, {
		node.release;
		keys.put(num, nil);
	});
	node = Synth.tail(
		nil, "umbSimpleFM",[
			\freq, {freq = num.keyToDegree(scale, 12).degreeToKey(scale).midicps},
			\amp, vel/127
	]);
	keys.put(num, node);
	[chan,num,freq,vel/127].postln;
};
MIDIIn.addFuncTo(\noteOn, ~noteOnFunc);

~noteOffFunc = {arg src, chan, num, vel;
	var node;
	node = keys.at(num);
	if (node.notNil, {
		node.release;
		keys.put(num, nil);
	});
};
MIDIIn.addFuncTo(\noteOff, ~noteOffFunc);
)

// cleanup
(
MIDIIn.removeFuncFrom(\noteOn, ~noteOnFunc);
MIDIIn.removeFuncFrom(\noteOff, ~noteOffFunc);
)

Thank you! I've been trying to figure this out over the last week!