WATCHJimmy Fallon, J.K. Simmons, and Billy Joel Spontaneously Break Into Song on The Tonight Show

Well, that was epic. The Late Show released a clip on Wednesday, Jan. 6 of host Jimmy Fallon, Whiplash star J.K. Simmons, and music sensation Billy Joel joining his band in an impromptu musical performance of the singer's famous hit The Longest Time.

Well, that was epic.

The Late Show released a clip on Wednesday, Jan. 6 of host Jimmy Fallon, Whiplash star J.K. Simmons, and music sensation Billy Joel joining his band in an impromptu musical performance of the singer's famous hit “The Longest Time.”

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During this "commercial break" video, it's evident that the unforgettable moment was completely unplanned — yet it still might be one of the best late-night television show's happenings to date!

Tune in to the video below!

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