If you like the Beatles, musicologist Howard Goodhall did a very good piece on Sgt Pepper and how the individual songs work and were structured. He can't sing for toffee but I found his explanations and the theory behind how the songs work (even if McCartney/Lennon/Harrison weren't consciously aware of it) very interesting. Think it's called "Sgt Peppers Musical Revolution" and used to be available on BBC I-player but, if not, it may be on you tube.