U2 Unveil New Song, 'Invisible,' During Super Bowl XLVIII

New track is available for free download for 24 hours only, with benefits going to (RED).

U2 certainly aren't strangers to the Super Bowl — their 2002 halftime performance remains one of the greatest of all time — so Sunday's Big Game (and the record-breaking audience it will presumably attract) was the perfect place to launch their latest single, "Invisible."

Of course, given just about everything involving the iconic Irish quartet, this was so much more than a mere premiere: As soon as it debuted, "Invisible" was made available for free through iTunes, with Bank of America donating $1 for each download to Bono's (RED) charity, which fights AIDS, Malaria and Tuberculosis worldwide.

The big unveiling came with an artful, black-and-white commercial that opened with a quick 1,2,3,4 run up, some militaristic marching drums, and Bono pacing down a catwalk.

Seconds later, the song — a classic, widescreen U2 rocker, complete with the Edge's trademarked windswept guitars, a chorus big enough to fill MetLife Stadium, and lines like "There is no them/there's only us" (though, to be fair, there's also a noticeable New Order feel to the track) — kicks in, and surrounded by a raucous crowd, the band tear through a performance while LED screens emitted sparks behind them.

"Invisible" will be available for free until February 3 at 11:59 p.m. ET. It's the second new song U2 have unveiled in recent months (the other being "Ordinary Love," from the film "Mandela: Long Walk To Freedom,") and the track more than likely is taken from U2's long-in-the-works 13th studio album, recorded with Danger Mouse and due sometime in 2014.