Partyin' Payoff

The bet was that Stephen Colbert would sing Rebecca Black's 'Friday' on 'Late Night with Jimmy Fallon' if the two could meet a Friday fund-raising deadline for the education charity Donor's Choose.

With a 4/1 finish line, many suspected an elaborate April Fools' Day prank. But on Friday's "Late Night," Best Friends Forever For Six Months Stephen Colbert and Jimmy Fallon delivered big time, with The Roots rockin' and American Idol Taylor Hicks joining in.