Robert Townsend's documentary, Why We Laugh, based on Darryl Littleton's book, Black Comedians on Black Comedy, makes its debut at this year's Sundance Film Festival. As we celebrate Martin Luther King Day and tomorrow's inauguration of President Barack Obama, it's timely for us to examine how black comedy has evolved and adapted over the years. Here Townsend talks about his project with the Sundance Channel:

After the jump, three short clips from the film. Enjoy!

Bill Bellamy talks about how Bill Cosby and The Cosby Show represented hope for his family as "America's favorite dad," while Townsend notes Cosby's universal appeal.

In this clip, Chris Rock says today's young black comedians sometimes only appeal to black audiences. Thanks, cable TV (he means Def Jam and BET).

Here is a clip to remind you Whoopi Goldberg was and is more than just the woman who presides over silly hour weekday mornings on The View.