Played guitar and sang on three episodes of the third season of
M*A*S*H (1972) as "Capt. Spalding". Songs included "North Korea Blues (Oh, Tokyo)", featured prominently throughout the episode "Rainbow Bridge". In 2004, he played one of the Cocoanut Grove singers (lead singer in tune "Happy Feet") in the
Leonardo DiCaprio film
The Aviator (2004), which
also starred
M*A*S*H (1972) alum
Alan Alda. Wainwright's two children played the other lead singers (of different eras) in
The Aviator (2004).