YES
Fragile (1971)
90125 (1983)
These guys haven't been drafted yet. They put out some really high quality prog during a 3-album run in 1971 and 1972. I'd have taken any of those but Fragile is usually considered their best and has their most famous '70s song, Roundabout. It was the first of two albums with their best lineup of Jon Anderson, Chris Squire, Steve Howe, Bill Bruford and Rick Wakeman. The proggy workouts were still pretty focused by the genre's standards, and the harmony singing set them apart from their other scene-mates.
Roundabout
South Side of the Sky
By the '80s, prog was out of fashion, and many of those bands who kept at it produced awkward, ill-fitting records. But 90125 (named after its serial number) was very different, probably because it was not intended to be a Yes record at all. The band had broken up in 1980. Squire and drummer Alan White briefly attempted to form a band with Robert Plant and Jimmy Page, then hooked up with South African guitarist/singer Trevor Rabin, who had several albums of more mainstream music under his belt. After bringing in original Yes keyboardist Tony Kaye, the band went to work on an album to be put out under the name Cinema. About halfway through the sessions, someone in power suggested to Squire that he bring in Anderson and release the material under the Yes name. Despite trepidation from Rabin, who had nothing to do with the Yes legacy, that is what they did, and Anderson added vocals and lyrics to a set of streamlined songs already mostly completed by Rabin, Squire et al. The result was an evolution into a new-wave-y sound that didn't sound forced at all, with just enough vocal and instrumental flourishes to please the old Yes fans. The record was a major commercial and artistic success and produced a surprising #1 hit, Owner of a Lonely Heart.
Owner of a Lonely Heart
Changes