Pretty sure there was a previous lengthy thread on just the same subject, and just how many songs are based on the same chord progression. (And I've previously mentioned the Clemnenti sonatina)
There was also a hilarious video clip on Youtube of this 'cellist who absolutely HATES Pachelbel's Canon because the 'cello only gets to play the same 8 notes all the way through. (Go on, Google it, past my bedtime to do the searches!)