Watch U2 Debut 'Innocence' Bonus Track 'The Crystal Ballroom' Live

Hardcore fans have been begging band to play track since beginning of tour

U2 were about halfway through their fourth consecutive concert at Chicago's United Center when Bono announced they were going to perform a song they'd never done before. "There's a bunch of people that have been on the road since we started this tour," he said. "I have no idea how they're paying for it. I have no idea how they've skipped school and work, husbands and wives. But they've been on the road and they've been asking for one song, so we kinda nearly figured it out. We'll tell you about it before we play it. It's called 'The Crystal Ballroom.'"

The track is on the deluxe edition of Songs of Innocence. Like nearly every other song on the album, it was inspired by the group's early days in Dublin. "The Crystal Ballroom was a punk club we used to play that was called McGonagle's in East Dublin," Bono told the crowd. "But historically it's called the Crystal Ballroom. That's where, historically, my mother and father used to go. I thought it was a bit weird we ended up at a punk club where my mother and father used to make out. Something just a little funky about that, in a good way."

The group has now played every song from Songs of Innocence (including the bonus tracks) besides "Sleep Like A Baby Tonight" and "This Is Where You Can Reach Me." Every show on the Innocence + Experience Tour so far has included "The Miracle (Of Joey Ramone)," "Iris (Hold Me Close)," "Cedarwood Road," "Song For Someone," "Raised By Wolves" and "Every Breaking Wave." At select shows, they have also broken out "California (There Is No End To Love)," "Volcano," "The Troubles" and the extra track "Lucifer's Hands."

U2 play their fifth and final show at the United Center on Thursday. They have soundchecked the War tune "Two Hearts Beat As One" before the last two shows, so it's possible that will surface at some point. They have yet to play anything from Zooropa, Pop or No Line on the Horizon.