Click the green flag and listen. Click the stage to switch between sawtooth wave and square wave.
This music consists of a single tone played at varied frequencies and intervals. To produce chord-like sounds, the tones are played in sequence really quickly (arpeggio). Even the internal speaker of a 1990s PC could have played this :) I made the music in BeepBox, using a single channel with the instrument type "chip wave". I made two versions. One with sawtooth wave, and one with square wave. Both are included in the project.