"The Grey Fox" was one of the first I thought of, too. It was indeed the Chieftains, playing the straight trad role--this was in my mind about when the great Celtic Scare of the 90's was starting to be unleashed (late 80's actually).

In another era entirely, I found the music for Malcolm X to be exceedingly marvelously chosen--it was mostly Sam Cooke, and there's never been a more poignant voice in popular music. You don't think of him in a political context, but boy, did this work.

God I love to hear that man sing!

Bill