According to the former Beatle, the EMI Group, which owns the mechanical rights to the group's recordings, is the last holdout in a long--and most definitely winding--road that has seen the Fab Four's work entangled in a web of complications and finger-pointing on its way to Apple's music store, where it has yet to land.

"To tell you the truth I don't actually understand how it's got so crazy," McCartney told Newsbeat. "I know iTunes would like to do it, so one day it's going to happen."

Well, Sir Paul. Perhaps we at can be of some assistance and give our readers a short overview of the .

By virtue of their very names, the relationship between the Apple Corps. and Apple Computer has never been particularly friendly. Troubles began at a time when the very idea of something like iTunes and iPods would have been considered more appropriate for a science-fiction movie than the family room; in 1978, Apple Corps., the holding company founded by the Beatles to manage their business affairs, . The lawsuit was eventually settled out of court for an amount that was originally estimated in the tens of millions of dollars, but was later revealed to be a mere $80,000.

As part of their first legal encounter, the two companies agreed not to encroach on each other's business: the Beatles would not produce computer equipment, while Apple would refrain from releasing music products. But, over the next 10 years, the two rivals ended up in court twice more, both times over Apple Computer's addition of music-related functionality to its computer lines; the computer maker's continued legal fight with its British namesake led developer Jim Reekes (who is featured in the documentary ) to christen the Mac's startup sound "sosumi," a thinly-veiled homophone of "so sue me."