Last night (Dec. 18), MNDR rocked out on 'David Letterman' with assistance from a string quintet, a drummer and Connor Cruise, son of actor Tom, who played synths, samplers and various other electronic gear. It was the second time MNDR have appeared on 'Letterman' -- back in 2010, they performed 'Bang Bang Bang' with Mark Ronson on the show.

Afterward, they celebrated the performance at the hip West Village watering hole Darby's Downstairs, where Connor spun records late into the night -- and where Tom's security detail stopped by to scope the place out, just in case Tom wanted to do the likewise. (He didn't.)