Moog is a brand name for a variety of early syntehesisers, named after Robert Moog (it's pronounced to rhyme with 'vogue')who was a pioneer in electronic sound. they have been largely replaced by computer technology, but they were pioneered by musicians like Keith Emerson and Rick Wakeman, and their early honking and dweebing sounds decorate a large number of 'progressive' albums of the 1970's.
The original Moogs were monophonic, and incredibly temperemental - a light shower in a thirty-mile radius would make them go wildly out of tune, so you needed a vast knowledge of electronics to match your musicianship in order to get along with them. Kids today don't know they're born .... (blathering on for twenty minutes ...)
See what I mean Andy, there's a guy on here called Moog. Hello Moog, thanks for making an appearance. Do you have a Moog? I would like an ARP2600 but what's the chances of Aliens coming from Mercury?
I've inherited several Moog LP's that belonged to my dad, mostly moog'ed-up versions of pop and easy listening tunes of the time. Apparently he played them to me a lot when I was a kid.....I think that explains a lot!