//This line is a comment
SinOsc s => dac; //Patch: Connect a sine oscillator, called s, to the digital-analog converter (to play out the speaker)
Std.mtof(60) => s.freq; //use the Std.mtof function to convert MIDI note 60 (middle C) to a frequency in hertz. Then set the frequency of s to that frequency, using the "freq" function 
2::second => now; //let 2 seconds pass before the next line of code is executed
220 => s.freq; //Set s frequency to 220Hz
0 => s.gain; //Set s gain to 0 (i.e., set its amplitude to 0 so it is silent)
.5::second => now;
880 => s.freq;
.5::second => now;
//When the virtual machine gets here this piece of code will exit: nothing left to do!