Diana Krall, Elvis Costello Make Merry With Stephen Colbert

Guests open 'Christmas Carol Week' on 'The Colbert Report'

When he's not busy handicapping his own chances of replacing Jim DeMint as one of South Carolina's U.S. Senators, Stephen Colbert is celebrating the season with a slate of guests singing Christmas songs with him this week on The Colbert Report. Last night, he took a credible turn on "Have Yourself a Merry Little Christmas" with Diana Krall and her husband, Elvis Costello, trading verses on the somber tune as guitarist Marc Ribot added to glistening piano lines from Krall.