U2 took the stage Monday night without Bono -- who's still recovering from that serious bike accident last month -- performing a pair of songs with Coldplay's Chris Martin and two more with Bruce Springsteen on vocals. It was part of a World AIDS Day event in Times Square called "A (RED) Thank You presented by Bank of America" that was somehow kept under wraps until earlier today.

The event began with Chris Martin joining U2 for "Beautiful Day" and "With Or Without You," and ended with Bruce Springsteen doing vocals on "Where The Streets Have No Name" and "I Still Haven't Found What I'm Looking For." In between, Carrie Underwood and Kanye West did short sets of their own -- The Edge joining Underwood on stage to play guitar on her song, "Change."

It looked strange and, at times, sounded even stranger. But it was great to see the band back on stage doing four of their biggest hits. If you missed it, we've got the full video and performance details on @U2 Tours.