Laurie Spiegel plays Alles synth - temporary replacement

This 1977 tape is one of the earliest examples of purely digital realtime audio synthesis. It manages to achieve an analog synth sounding quality, but it is entirely digital synthesis and signal processing. The interactive software I wrote and am playing in this video recycles my keyboard input into an accompaniment to my continued playing, which is why I called it a “concerto generator“. I use part of one of the keyboards for control data entry, and the small switches upper right to access pre-enter