AC/DC is one of the highest-grossing bands of all time, but until today, you would have struggled to find their music in digital form via any legal means. Why? They were one of the last great iTunes holdout bands, refusing to sell their music online in order to preserve the hallowed “album” format. Looks like they finally realized the battle’s lost, though. Now the Australian hard rockers have finally released their entire back catalog to the iTunes Store..