Here's Bruce Willis getting down on the harmonica in Harlem, singing and jamming out on stage during a jazz show ... and the video is amazing!!!
We got these clips of Bruce at The Apollo Theater last week, where he and lots of celebs showed up to salute the Jazz Foundation of America ... and ya gotta see Bruce bring the house down!!!
Bruce was one of the last acts to perform, and you see him showing off his pipes and playing the hell out of the harmonica during a 5-minute solo set with the jazz band, Sweet Georgia Brown. The song he's singing is his very own, "Devil Woman."
Other celebs joining Bruce at the event include Common, Keegan-Michael Key, Danny Glover, Patti Smith, Tony Bennett, Quincy Jones and Bettye LaVette.
We're told Bruce's performance was a big hit ... the crowd started chanting "Bruno," his musical alter ego.