Constellation

A concept for a suite of synths, developed by Moog Music in the 1972-74 timeframe. The Constellation was an attempt by Moog to, in part, overcome the limitations of technology at the time which made a versatile polyphonic synth impractical. The suite was to have included three units, with an integrated stand to incorporate all three:

The Apollo, a polyphonic synth, probably with limited patchability but intended to be more versatile than a string synth. (Exactly how this was to have worked was left unspecified in the advertising materials.)
The Lyra, a monophonic synth with more features and more patching versatility than the Minimoog.
The Taurus, a bass synth incorporated into a set of bass pedals.

The idea was that the performer would use the Apollo to produce the types of string, organ, and piano sounds that Moog figured would be most likely to be desired in a polyphonic synth, especially by performers who were moving over from conventional keyboard instruments. The Lyra would then be used to produce more complex timbres and effects that the Apollo was not capable of. The Taurus would save the peformer, who would be quite busy with the two keyboards, from having to play bass parts with his left hand.

Of the three synths in the Constellation, only the Taurus made it to market in a form near to which it had been conceived. (And it wound up being used by guitar and bass players as much as by keyboard players.) The Apollo ran into a host of developmental problems; all attempts by Moog to make it at least a little more versatile than a string synth wound up costing too much and potentially not fitting within the case. A few Lyras were built and sold before Moog decided to take a step back from the whole concept. At several levels removed, the Lyra eventually morphed into the Multimoog. Keith Emerson, as an important figure in the development of Moog synthesizers was given a prototype and actually used it extensively on the album Brain Salad Surgery by Emerson, Lake and Palmer. There the Lyra and the Apollo synths can be often heard. (But not the Taurus, which wasn't of Emerson's interest, since he was not a pedal player.) Emerson returned the equipment to Moog Music after touring with it.

However, the Constellation wasn't the end of Moog's efforts to build the much-sought-after polyphonic synth. Taking some basic concepts from the Apollo, and applying some application-specific integrated circuit technology which was becoming practical in the mid-1970s, this produced the Polymoog. Unfortunately, in use the Polymoog turned out to have not solved all of the Apollo's problems, and so its popularity was short-lived. Moog didn't produce a practical polyphonic synth until the Memorymoog.