Sarah Meisels writes ...
The Beatles’ video of Hey Jude was shown on the David Frost show on September 8, 1968. They were tricky, all of them: David Frost made it seem that the Beatles were actually in his studio, but they weren’t.
David went to Twickenham film studios four days earlier, on September 4. The Beatles were there filming the videos for Hey Jude and Revolution. There was even a live audience at Twickenham for the filming.
David recorded his introduction at Twickenham on Sept. 4. The Beatles played the David Frost theme song live that day. But the music for both Hey Jude and Revolution was pre-recorded.
Paul sat at the piano and pretended to play. No one played anything. Even the 36-piece orchestra was faking it.
However, the singing is live. Both the lead and backing vocals were recorded live that day in front of the audience.
Sometime between 1966 (when the Beatles mimed singing in their Rain and Paperback Writer videos) and 1968, the Musicians’ Union had banned miming. So the Beatles sang, but didn’t play.
Beatles Bible says that Paul sang along to his own studio vocals that day. I don’t quite see how that was possible, but that’s what they say. It also says that his ad-libs in the fade-out were entirely live.
They filmed at least three takes, and then combined takes one and three to make the film most of us have seen.
The Revolution video was filmed the same way: The Beatles sang to a pre-recorded backing track.
Why they decided not to play anything, I can only guess. They wanted it to be great, of course. They also had been extremely stressed out for their Our World performance of All You Need Is Love. For that performance, John sang live, Paul played bass live, George played a live solo, and Ringo played a drum intro.
That came off all right (with some overdubbing afterward), but I don’t think they wanted to go through that stress again and be unsure of the outcome.
So the answer to your question is that Paul played bass…and piano.
