Watch Billy Joel, J.K. Simmons and Jimmy Fallon Sing Improptu ‘For the Longest Time’

When Billy Joel is visiting your show, it’s hard to resist breaking out into one of his many signature songs. And though Jimmy Fallon is the king of getting his guests into conveniently amusing situations, an impromptu song sesh during a commercial break on Wednesday night’s show seemed to be truly unplanned.

With Joel and J.K. Simmons as guests, Fallon and the rest of the gang broke out into a cover of “For the Longest Time,” with Joel and Fallon taking turns singing the melody and Simmons lending his rich basso to the lower notes. As Fallon himself said, “That’s the way to do it.”