Generate classic waveforms

There are certain wave types that are historically used in electronic music, known as "classic" waveforms: sine, sawtooth, square, and triangle. These are the four waveforms generated by the classic Moog synthesizer oscillators, and are still quite useful in computer music.

Linear motion in two voices

Two oscillators, one in the left channel and one in the right channel, play notes that have a continuously changing frequency, at a continuously changing note rate. Every few seconds (some randomly-chosen number of seconds from 2 to 8) each of the two oscillators gets a new destination frequency and destination note rate, and heads toward those destination values over the next few (randomly-chosen number of) seconds.