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SinOsc m => SinOsc c => dac; // modulator to carrier

400 => c.freq; // carrier frequency

201 => m.freq; // modulator frequency

1500 => m.gain; // modulation index

2 => c.sync; // FM synthesis (sync is 2)

while( true ) 1::second => now; // time-loop

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And now for the SC equivalent

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{var carrier = 400; // carrier frequency

var modulator = 201; // modulator frequency

var index = 1500; // modulation index

var m = SinOsc.ar(modulator) * index; // modulating signal

var c = SinOsc.ar(carrier + m); // frequency modulation (carrier + modulating signal)

Out.ar (0, c ! 2)}.play

////////////////////////////////////////////////////

and now a phase modulation example in SC

////////////////////////////////////////////////////

{var carrier = 400; // carrier frequency

var modulator = 201; // modulator frequency

var index = 2pi; // modulation index

var m = SinOsc.ar(modulator) * index; // modulating signal

var c = SinOsc.ar(carrier, m); // frequency modulation (carrier + modulating signal)

Out.ar (0, c ! 2)}.play

////////////////////////////////////////////////////

note, the SinOsc in SuperCollider takes frequency input as the first variable in parenthesis, and phase (in radians) in the second.

cheers