SinOsc sl => dac.left;	// connect a sine oscillator to dac left chan
SinOsc sr => dac.right; // connect another sine to dac right channel
300.0 => sl.freq;		// assign 300.0 to the frequency of left sine
sr.freq(302.0);		// assign 302.0 to frequency of right sine
5.0 :: second => now;	// hang out for 5 seconds
304.0 => sr.freq;		// set right sine freq to 304 Hz.
4.0 :: second => now;	// hang out another 4 seconds