I've always loved the line "I'm dappled and drowsy and ready to sleep", crafted with a great melody

Couldn't agree more, etaoin. Talk about getting great value out of one (admittedly excellent) guitar phrase.

Full lyrics at:
http://www.geocities.com/just_4_u333/simonandgarfunkel.html#The59thStreetBridgeSong
for those interested.

Just in passing - off the top of me head I can only think of one song that repeats the same chord sequence absolutely all the way through, being With or Without You. And I can't think of any song that repeats exactly the same picked guitar part. 'riff' isn't the right word here, I think. Then again... I feel a new thread coming on!

Fisk

P.S. Another absolute blinder, Milo - brightened my day again