For years, the Beatles have been conspicuous by their absence on iTunes and other download sites. And their music has only been available on CDs mastered in the digital dark ages.Now, at last, newly re-mastered CDs are in the shops, with rumours of a download flood to follow. But what took them so long? The simple answer is money – and a web of legal complications that has kept generations of lawyers busy. These days, there are four key players: Paul McCartney, Ringo Starr, John Lennon’s widow Yoko Ono and George Harrison’s widow Olivia. Before anything can be done in the Beatles’ name, all four have to agree. And often that simply hasn’t been possible. Paul and Yoko have argued about whether the Beatles’ songs should be credited to Lennon/McCartney or McCartney/Lennon.