Watch Halsey, Brandon Flowers, Channing Tatum & Tons More Sing a Song for a Good Cause

Last night on Jimmy Kimmel Live!, a bevy of stars came together to form a supergroup known as The (RED) Pack, a reference to the HIV/AIDS-fighting organization (RED). Bringing the grand piano-aided, awareness-raising song and dance were DJ KhaledHalseyThe Killers frontman Brandon Flowers, Kristen Bell, Channing Tatum, Neil Patrick Harris, Julia Roberts and one of (RED)'s biggest spokespeople, Bono.