Not sure what type of keyboard player you are looking for but here is some info on some progressive rock players.
http://yescography.tripod.com/home.htm

This will take you to a site about the band Yes. Check out links to Rick Wakeman, Patrick Moraz, Geoff Downes - these links lead to lots of other famous keyboard players of the 70s. Also a web search for Nick Mason will give you a great deal on this great Pink Floyd keyboard player.

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