(Amended November 20, 2010.)
Wow... David Bowie performing "Life on Mars" and "Ashes to Ashes" on The Tonight Show, September 5, 1980. Johnny Carson's first guests that evening were Bob Hope and Richard Pryor. (Note Bowie's acknowledgment of Pryor following "Mars.") Carson's professional reserve is, for this observer, wholly admirable.
Link supplied by TLASILA's very own Don Fleming, with thanks!