A five octave keyboard produces pitch and envelope control voltages, and permits the real time "playing" of a wide variety of electronically generated sounds.

From "Ultra-Short Form Catalog of Electronic Music Composition Instruments", R.A. Moog Company, October, 1965.

This manual controller uses a conventional five-octave organ keyboard. Discrete, equally spaced values of control voltage are selected by depressing the appropriate key. The difference between control voltage values is 1/12 volt, and is adjustable over a +/- 10% range. A "memory" circuit holds the control voltage corresponding to the last key to be depressed. A portamento circuit introduces a time lag between the depressing of a key and the control voltage change, thereby making it possible for the control voltage to "glide" from one value to another. In addition to the control voltage, the keyboard produces a trigger which initiates the cycle of any number of 911 envelope generators. The keyboard is housed in its own attractive hardwood enclosure, 40" long, 15" deep, and 4" high. Controls for adjustment of the voltage difference between keys, for degree of portamento, and for the memory circuit are placed at the left cheek of the keyboard.

From "Electronic Music Composition - Performance Equipment, Short Form Catalog - 1967", R.A. Moog Company, 1967.