DNCE Sets Up for Surprise NYC Concert

Joe Jonas and the rest of DNCE are playing a free, impromptu show to celebrate the band's 1st album, soooo ... traffic alert, NYC!

Their stage popped up Thursday afternoon at Penn Plaza, and we're told the band will plug in around 6 PM ET ... one day before their album drops.

Sources tell us they just wanted to do a show for kicks and giggles, and that's all there is to it. Doesn't hurt in the promotion dept either.

Ah ya ya ya ya!!