Two-voice music programming system: The PDP-9 as an automatic electronic organ

A small computer was programmed to translate two-part musical scores into tables of numbers which were then used in the execution of the music through an amplifier and loudspeaker. The objective was to create sets of tape recordings to be used in psychophysical testing of the discriminabilities and preferabilities of music played on different pitch scales. The close tolerances in the timing of events in such stimulus materials demand special programming techniques and hardware components. The working system is described, and recommendations are made concerning the main features of an improved system.