U2 unveiled a new single called "Invisible" during the Super Bowl XLVIII to the delight of fans around the world. The Danger Mouse-produced song was a project between Bank Of America and RED, Bono's charity to fight mainstream diseases like AIDS, tuberculosis and Malaria. The band encouraged everyone to download the song for free with Bank of America donating 1$ per download of the track to the Global Fund.

U2 front man Bono revealed to USA Today that 'Invisible' is not part of the new album they are working on and that an official single is set to be out later this year: "We have another song we're excited about to kick off the album," he confirmed. "This is just sort of a sneak preview, to remind people we exist."

Despite recent Oscar nomination for their Golden Globe-awarded "No Ordinary Love", the band is not thoroughly confident about their relevance in the industry.

Talking candidly to Zane Lowe of BBC Radio 1, the "New Year's Day" singer revealed: "We're on the verge of irrelevance. You have to make stuff relevant to you and where you're at, make an honest account of what you're going through. If that's relevant to other people, great. But we don't know."

However, the band is excited when talking about the inspiration behind their untitled thirteenth studio's sound, saying: "We went back to why we wanted to be in a band in the first place. We were listening to the Ramones and Kraftwerk - you can hear both on 'Invisible'. It opened up a whole valve for me writing, it was like a damburst of sorts."

Their outburst of uncertainty did not affect the motivation of the Irish band to once again prove to the world why they were once considered the biggest band in the world.

U2 concluded the interview with their desire to tour smaller venues: " We love those big outdoors shows - we've had some of the best nights of our lives [playing those]. For this album, we're going to start indoors. We'd like to play the O2 [arena]. Sometimes it's nice to play intimate things like that."