From 1968 or so to 1980 you had a progressive rock Yes. People came and went, but the music was pure prog goodness!
Bill Bruford then Alan White
Tony Kaye then Rick Wakeman (mostly)
In 1980 Yes was over. Squire and White were all that was left. They met with Jimmy Page to attempt a new band—-XYZ (ex—Yes Zeppelin). It didn’t pan out. Page went to The Firm.
Squire and White met Trevor Rabin and they started a project of mostly Trevor-penned more mainstream rock songs. They started a band, named it “Cinema.” Enter Tony Kaye returning on keyboards and Squire asking Jon Anderson to return and you have a Cinema band that was really mostly Yes Men….so, they reformed Yes. Because they didn’t record in Europe as the prog era version did, they were LA-based, more popish and radio friendly, people called them Big Generator Yes or YesWest. West Coast, mainstream sound, big hits, radio friendly, less proggy.
Thanks, I knew all those details but didn't know about the East/West tag. The couple of mentions I'd seen on here were the only times I'd ever heard it.