Serge, Buchla, West-coast Modules?

What was the first electronic musical instrument you designed?
My first instrument was based on the idea of analyzing the shape of the hand, in order to translate that shape into the equivalent waveshape. By moving your hand, you could change the waveshape, and thus the timbre, of the sound. The first instrument used a motor-driven scanning wheel, which extracted information about the position of the hand along two axes, the horizontal axis relating to time and the vertical to amplitude, essentially. So if you held your hand with the fingers parted and parallel to one another perpendicular to the time axis, you would get a square wave with five times the fundamental frequency. If you slanted your hand, you would smear the rise time of the wave so that the harmonic content became less, and if you put your fingers together you would extract more of the fundamental. As you moved your hand around, you could change the timbre in very rapid and responsive ways. This instrument had the disadvantage that you didn't have access to a variety of pitches, but at that time the usual way of dealing with pitches in classical electronic tape studios was to record a lot of segments at different pitches and splice them together. Later we built a unit that used a cathode ray scanner, which was much more responsive.

How did your design concepts develop from there?
Oh, we got into sequencers and voltage-controlled oscillators. It didn't take us long to arrive at the concept of voltage-controlling all of the parameters that could possibly be regarded as significant musical variables, including such things as voltage-controlled reverb and voltage-controlled degree of randomness. It did take us a few years to find truly general ways of dealing with the voltages that did the controlling. That turned out to be the bigger problem.

What do you mean by 'truly general ways'?
Most of the current electronic musical instruments that you'll see have fairly limited methods of generating and routing control voltage shapes. Sequencers generally output only series of discrete voltages. Envelope generators are often limited to creating shapes that can be described by such terms as attack, initial decay, sustain level, and final decay. Low-frequency oscillators offer only a few waveshapes, and they operate within a narrow frequency range. And these are the only three control voltage generators that one would expect to find in the so-called traditional synthesizer. In other words, the designers of these instruments make very stringent assumptions about what shapes are esthetically acceptable in the way of, say, envelopes.

Where did these limiting assumptions come from?
The sequencer is thought of primarily as an automated substitute for a piano or organ keyboard, on which one has access only to discrete static pitches. The LFO is thought of primarily as a vibrato oscillator, so it's designed only to do what a violinist or vocalist does in the way of adding vibrato to a tone. And the envelope generator is based on the note forms created by percussive instruments, which are loud at the onset and decay smoothly, and by sustaining instruments of the wind and string families. In other words, instrument designers still think that all notes should be shaped the way traditional acoustic notes have been shaped. Electronic instruments are obviously capable of much more than this, but the electronic possibilities are still being made subservient to our traditional acoustic experience.

But the instruments you design aren't limited in these ways.
I would hope not. Our instruments incorporate what we call arbitrary function generators, with which you can generate any kind of shape you want. The instrument doesn't force you to make any assumptions about what are pleasing shapes and what are not. That has to be decided on a musical level.