Many computers are capable of making music by hard-wiring their low-order bit to a speaker system and simply turning this bit on or off rapidly. Experiments with the PDP-1, undertaken by MIT undergraduate Peter Samson, however, went a step further and showed the computer was capable of producing four-note polyphony.
Creation of a ‘harmony compiler’ by Samson allowed for sophisticated music to be played and soon the total quantity of music encoded for the PDP-1 reached several hours. Student Bill Ackerman encoded a version of all four movements of Mozart's Eine Kleine Nachtmusik
which may have been the longest single musical work ever played on a PDP-1.