(
SynthDef(\sine, {
    arg freq=440, amp=0.1, atk=0.01, dec=0.1, sus=1, rel=1, out=0;
    var sig, env;
    env = EnvGen.kr(Env.new([0,0.9,0.6,0.6,0],[0.8,0.3,1,0.5]));
    sig = SinOsc.ar([freq,freq*1.01]);
    sig = sig * env * amp;
    Out.ar(out,sig)
}).add;
)

Synth(\sine, [\freq, 660]);

().play;

(
p = Pbind(
    \instrument, \sine,
	\freq, Pseq([Prand([100,150,200],inf),Prand([200,250,300],inf),Prand([300,350,400],inf)],inf),
    \amp, Pexprand(0.01, 0.15, inf),
    \atk, Pseq([0.01, 0.5, 0.1],inf),
    \dur, Prand([0.5,1,5],inf),
	\midinote, Prand([30,40,50],inf)
);

x = p.play;
)

x.stop;