Viewers who tuned in to "The Late Show" last night got a special treat when the always funny Jim Carrey broke out into song. After his interview with David Letterman, Carrey admitted that he really has always wanted to be a singer and got Paul Schaffer to play him a tune that would really prove his abilities once and for all. Shaffer's choice? "Take On Me" by A-Ha. Check out Carrey's performance of the 1980s classic below.