I'm going to have to agree with Father Jack on this. Although, I do cede that neither Floyd nor Zeppelin were repetive, they certainly joined a motion already in full swing. Remove the Beatles, and rock & roll is still Elvis when those boys come into play. The Beatles certainly progressed and changed as time moved on. they all got better and brought what they learned to the group.

I do see how you can say that Zep is repetive, yet it is not so. each song is different, but a very distinct style. as with Floyd. The Beatles have a recognizeable sound, but you certainly can't stylize their music under any one genre. There's Revolution 9 and Across the Universe, and Lucy in the Sky for the pyschadelic sound. I Wanna Hold Your Hand, She Loves You, Ticket to Ride, as examples of their pop rock style. Rocky Raccoon for the Country/narration style. Something, Strawberry Fields, Let It Be for the slow, chilled out music examples. Abbey Road if you're looking for a flowing album. They have so much of everything, and created so much of it that without them, such great bands as The Talking Heads, Yes, Floyd, and Zep do not exist.

~edit: Oh, and i almost forgot. When I'm Sixty-Four and All You Need Is Love for the swing.

__________________
Don't let anyone tell you what you should do. Things are always simpler, and yet more complicated than they seem.