Zappa did a hilarious and very musically adept cover of "Stairway to Heaven" in which a full horn section plays the lead solo note-for-note. I would have though this one uncoverable until I heard Zappa pull it off with his usual panache.

I like suggestions like "Imagine" and "Free Bird" and "Subterranean Homesick Blues" because the structures are very simple, making them quite possible for all of us to attempt...but the originals are so good that it makes us crazy to try. Still, there is always a way to arrange something to your own advantage.

I love Johnny Cash, but I cannot stomach his version of "It Ain't Me, Babe". Same goes for John Lennon and Harry Nilsson--they're both heroes to me, but I don't like their collab version of "Subterranean Homesick Blues".

http://www.soundclick.com/MarkKaufman