I've heard this by Valdy and by Pete Seeger, but a Google seartch gave me this Leonard Cohen version:

http://www.scribd.com/doc/107710/cohen-leonard-passing-through-chords

It seems to me that both Valdy and Pete put another chord in over the word "late" in the line "it's gettin' late", but I don't have an instrument with me so I can't be sure.