Chip Tunes are pices of music written to be performed by a (usually very basic) sound chip. The most common example is probably early computer game music or ringtones for mobile phones.
There is also a substantial part of the mod scene (a community of people making music to be played on the Commodore Amiga or using tracker programs) making chip tunes, not for specific tone generating hardware but with the same feel to them.
Generally they consist of basic waveforms, such as sine waves, square waves and sawtooth waves, and basic percussion, often generated from white noise going through an ADSR controlled amp.
On the one hand, they can be an art form in their own right. On the other, if you listen for too long, you may get listening fatigue.
