U2 And Christina Aguilera Will Not Be Riding Their Wild Horses This Summer

U2 and Christina Aguilera have both postponed their summer tours, thus reducing the number of big-name tours with headliners who don't have to be referred to as "nostalgia acts" to an even-smaller number. (No, really, have you looked at the roster for your local shed? Scorpions, Foreigner, Yes, Chicago — it's like 1983 never ended up.) U2's jaunt, which included a headlining stint at the Glastonbury Festival, has been moved to 2011 because of frontman Bono's back surgery; the Aguilera tour has been ditched until next year because the singer "needed more time to rehearse the show," according to a statement from Live Nation, the concert megapromoter that's putting on both those shows. (I wonder how that corralling of the entire large-scale live-music market is going for them? Eh, whatever, they'll probably just add a few "facility charges" to make up for the lost U2 revenue.) In related Aguilera news, her forthcoming album Bionic leaked last night; the record is 18 tracks and includes cameos from Nicki Minaj, Lil Jon (really?), Le Tigre, and Peaches. "My Girls," which features the latter two, is embedded after the jump.

I'm still giving Bionic a first spin, but one thing that's marked its best tracks so far is Christina's willingness to rein in her super-sized pipes and have fun with her voice. "I Am," a collaboration with the deliberately oddball singer Sia, is particularly satisfying on this front.