This is a cool thread. About Sgt. Pepper's, as an album of songs I prefer Revolver but Sgt. Pepper changed the future of rock music forever. It was more than an experiment in new studio technology, that record changed what rock music could be. One could argue that prog just to name one genre might not have developed had it not been for the Beatles in 1967. I do happen to think the album contains mostly great songs, but its importance just can't be overstated.