Rock group U2’s new single “Invisible” raised more than $3mn for the fight against Aids during the 36 hours it was available for free on iTunes, it was revealed yesterday.  It scored more than 1mn downloads in the hour after it premiered in a Bank of America commercial during Sunday’s Super Bowl, then picked up 2mn more until the free offer ended Monday midnight (0500 GMT Tuesday.)  With the second-biggest bank in the US pledging one dollar for every download, Invisible raised more than $3mn for the Global Fund to Fight Aids, Tuberculosis and Malaria.  The song now is selling on iTunes for $1.29 with all proceeds going to the Global Fund, said (RED), a charity co-founded in 2006 by U2 frontman Bono to engage big consumer brands in Aids fund-raising, in a statement. “We are very thrilled with this, ‘Invisible’, it sounds great and it feels good,” Bono told Britain’s BBC Radio One pop music station Monday. “We’re just delighted there are still people very interested in us.” The Bank of America, which made $3.4bn last year, has committed $10mn over two years to fight Aids in a partnership with (RED) and U2.