On the Lennon Box Anthology, George Martin is credited with the orchestral arrangement on GROW OLD WITH ME (which, even if not credited, one could have heard a mile away-- and that is meant in a complimentary way).
There is also an uncredited bass in the background, and the style playing is very McCartney-like. Now, I had heard the remaining three (during Beatles Anthology) had worked on this song, but eventually scrapped it.
Is that or is that NOT Paul McCartney playing bass on the backing of GROW OLD WITH ME?
(The original version is on MILK & HONEY, and it's just John and piano, obviously a crudely recorded demo, with no other instrumentation).



