Last week, President Obama joined country legend Willie Nelson on stage for an all-star version of Nelson's hit 'On the Road Again.' Instead of just introducing the singer, Obama stayed to sing.

John Fogerty, Mary J. Blige and rapper Common were among the other stars on stage during the 'In Performance at the White House' finale. The event aired on PBS on Friday night (Nov. 7), although the show was taped one day earlier on the South Lawn of the White House.

The clip shows that the president takes a few minutes to warm up to the song. While his dancing is spirited, he doesn't jump in during the singalong until it reaches its second chorus. The moment got the best of First Lady Michelle Obama, however -- partway through the performance, she makes a grand entrance and joins the gang in dance and song.

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