Backbeat: Diplo, Skrillex, Kaskade, Nero and No Doubt Take to the Rooftop for (RED)

Above, Skrillex and Diplo go back-to-back on the roof

Amidst the insanity of GRAMMY Week, a super hot, (mostly) invite-only party took place in a rooftop penthouse in Downtown LA. Capacity? A few hundred. Crowd? The elite, industry insiders, and a few lucky fans.

Skrillex and No Doubt's Adrian Young (Getty Images)

Kaskade and Tommy Trash kicked the night off in quick succession, leaving Diplo and Skrillex to go back-to-back on the decks for the latter part of the evening. At one point, Diplo admonished the crowd and press for the amount of photos and videos being shot. After that, the crowd of about 100 put away their cameras and phones and (mostly) kept them away for the rest of the night.

Actor Jesse Williams (Getty Images)

Nero joined Diplo and Skrillex on stage just after 1am and, after going back-to-back with Skrillex and Diplo for a few tracks, treated the crowd to a semi-live rendition of “Promises” -- vocalist Alana Watson was in attendance, and wasn’t shy about hopping on the mic to sing over the track.

The who’s who of EDM were in the building, and stars like No Doubt (excluding Gwen) and actor Jesse Williams turned out to support, drink, and party.

The event was put on to help support the DANCE (RED), Save Lives album, and the entire lineup for the night also appear on the album.

Spotted at the event: Kevin Gimble (Circle Talent Agency), Christine Silver (Insomniac Events), Drew Best (SMOG), Nathan Hayes (Atlantic Connection Music/SMOG), Kill The Noise, Brent Burns (KickKickSnare), Danny United, Lee Anderson (AM Only).

No Doubt (sans Gwen Stefani) on the red carpet (Getty Images)