VIDEO: Watch as Jay Leno gets his goodnight serenade

Over the years, Jay Leno has often referred to comedic contrarian Bill Maher as "a friend of show". Indeed he's had Maher on as a guest more than 50 times. So it made sense, as Jay's days as host dwindle to a handful, to bring back the bracingly candid libertarian one more time. But why so dressy, Bill?

The reason became apparent after an interview about the State of the Union speech and legalizing pot (Maher's bête vert). He had a surprise planned for Jay, a musical tribute he compared to Bette Midler's famous performance on Johnny Carson's second to last show, when she adapted the words to the standard "You Made Me Love You".

Neither Maher nor Leno is much of a sentimentalist, so Bill brought out a duet partner with a decidedly slashing sense of humor: Seth MacFarlane. Their version of "Thanks for the Memories", Bob Hope's old theme song, was quite a bit more barbed, focusing on Leno's rivalry with fellow late night host David Letterman ("You crushed him in the ratings/You'll take that to your grave") and his ill usage at the hands of NBC ("You've been retired and twice been fired/For being #1, so thanks").

Guess this lets Garth Brooks off the hook. He'll be the musical guest on Jay's final show next Thursday. Now he can just sing "Happy Trails."

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