You never know when U2 is going to surprise you.

On the last day of May, they took to the rooftop of Electric Lady Studios -- where they were working on their new album -- to film an acoustic performance of "Sunday Bloody Sunday." They've now posted that video on their website and dedicated it to democracy in Iran as part of Bono's ONE's campaign to "harness the power of protest songs to demand action against extreme poverty at the G8 summit."

As the 2013 elections approached, the band was asked by Iranian human rights activists to contribute their music.