The guys who play with Paul McCartney do songs they didn't have any part in writing or arranging note-for-note like the recording. Except for having McCartney in the band they are not doing anything different than tribute musicians other than not having to look like one of The Beatles. I'm sure any musician from the best Beatles tribute bands could take their places.
Doing a top-notch Beatles tribute while not extremely demanding musically does require extraordinary vocal talent. There is also an initial investment which could likely be in the tens of thousands of dollars in getting the correct period guitars, amps, and drums as well as stage clothing. Few musicians have the required talent to pull this off let alone the ability to pull off the right look.
We've gone the Beatles route, but are by no means impersonators. We just enjoy what we do and add our own twist, and others seem to enjoy it as well. However, we do have the vocals pretty well nailed:
