The way we listen to music is ever changing. Less than 30 years ago, vinyl was the main medium for albums, then it was cassette tapes. The CD took over by the 1990s, but didn’t really last because digital music took over, thanks in part to Apple’s iTunes. What format will music be delivered to us in the future? Will we eat it like a cupcake? Will it be injected into our blood stream? I doubt it, but these are the things that U2 and Apple are thinking about right now as they brainstorm on the digital music format of the future.