After Simian Mobile Disco took the stage Sunday evening at Brooklyn, New York's East River State Park for the weekly JellyNYC Pool Party, the London-based electro duo were joined by a few surprise guests. While this might sound like a normal concert occurrence, in this case the guests were a surprise to the band, not just the crowd.

During SMD's headlining set, members of an earlier act, Athens, Ga. collective Dark Meat, crashed the stage, complete with face paint and live marching band instruments -- including a trumpet and trombone -- much to the surprise of the both the Jelly staff and the headliners. Confusion was relieved once the guys were removed a few minutes in. The tuba player, meanwhile, never made it on stage, but ended up walking into the audience of thousands and crowd surfing while playing his rainbow colored instrument.

In the end, SMD didn't seem to mind too much -- they just laughed and shrugged it off, continuing to pound away at the decks for the thousands of dancing partygoers, who were none the wiser.