SinOsc modulator => ADSR menv => SinOsc carrier => ADSR cenv => dac;
2 => carrier.sync;       // setup carrier input for FM
cenv.set(0.1 :: second, 0.1 :: second, 0.5, 1.0 :: second);
menv.set(0.1 :: second, 0.2 :: second, 0.3, 1.0 :: second);
1000.0 => carrier.freq;  // roughly the spectral center
100.0 => modulator.freq; // roughly the "pitch", or inharmonic
500.0 => modulator.gain; // make this enough to do good modulation

1 => cenv.keyOn => menv.keyOn;
0.2 :: second => now;
1 => cenv.keyOff => menv.keyOff;
2.0 :: second => now;

200.0 => modulator.freq;         // octave higher, but "formant" still at 1K
1 => cenv.keyOn => menv.keyOn;
0.2 :: second => now;
1 => cenv.keyOff => menv.keyOff;
2.0 :: second => now;

117.3 => modulator.freq;         // inharmonic
1 => cenv.keyOn => menv.keyOn;
0.2 :: second => now;
1 => cenv.keyOff => menv.keyOff;
2.0 :: second => now;