Moog Polymoog from inside cover of Contemporary Keyboard Magazine November/December 1976.
This ad ran in September/October and November/December 1976 issues of CK, right after the magazine announced the Polymoog synthesizer in the Spec Sheet section of the July/August 1976 issue. That Spec Sheet announcement provides a great description of the machine:
"The Polymoog utilizes 72 micro-ships that enable the performer to play 72 synthesized notes simultaneously. Each chip holds two VCAs, one VCF, and one contour generator, thus providing each key with its own volume, attack, and brightness response. Two oscillators provide the basic patches. Programming is done in two ways: 1) With eight preset modes - piano, strings, harpsichord, organ, vibes, funk, brass, and clav.; 2) From scratch, as in the standard monophonic synthesizers. Control voltages are supplied by an LFO that produces sawtooth and pulse waves, and the keyboard may be split for getting separate effects in the bass and treble registers."That pretty much sums it up!
End note: Did you catch the error in the description? It says that there are 72 chips for the 72 notes. There are actually 71 keys on a Polymoog (E to D), but the prototypes given out to famous Moog users such as Chick Corea had 72 keys. They must have used the prototype description for the Spec Sheet copy. Find out more about the note changes on dubsounds.com's Polymoog pages.