SGT. PEPPER'S LONELY HEARTS CLUB BAND

This is certainly a great album. I listened to it a lot when I was growing up. From a progressive rock stand point I'd really only buy it if you are a prog-buildup completionist. Off the tip of my head there aren't any styles demonstrative of the progressive genre. Lennon throws in some interesting animal noises and the finale (great, by the way) track features very disparate sections combined in a meaningful way.

A strong album from the Beatles, but *almost* irrelevant for building up a progressive rock collection. Aside from most western bands being influenced in a direct or roundabout way by the Beatles it is difficult to link the sound on this album to any of the sounds that make prog a unique genre.