Harmonix has said that The Beatles appearing in Rock Band 2 was mostly down to a "chance meeting".
John Drake, PR at Harmonix, told OXM that "it sort of was a chance meeting. There were two layers to it. One layer was we were talking to them already, because we're talking to everyone all the time trying to get as much music as possible into the world of interactive music gaming.
So they were talking on the business side already and then Van Toffler, the president of MTV Networks and Danny Harrison, George Harrison's son, and Olivia Harrison met on family vacation. They sort of ran into each other and started talking. I guess the Harrisons were fans of Rock Band!
So all these things came together. The band members and legacy of the band members sort of found out about us and obviously we're huge fans of theirs. For the particulars of it, we should put you in touch with someone at MTV. But that's the anecdotal story, it's really, really cool."
For five other things you didn't know about Rock Band, check out our feature.