Last week, we told you about Anna Kendrick and how she auditioned for Pitch Perfect. She had found a video online of a girl performing a song with a cup, thought it was cool and she spent a day learning it. For no reason other than thinking it was fun.
Last week when she was on Late Show with David Letterman, Letterman surprised her with a cup and asked her to perform it for him and the audience. Check it out below!