Such a pretty song.
I heard that the original was very Liverpool-centric & George M & Paul suggested he make it broader, lyrically, but keep everything else the same.
It's fun to be able to play that theme between the verses. Obviously, I left out the faux harpsichord solo.

George Martin played, but it wasn't an electric harpsichord.
They wanted to put a Bach-like piano part on it, but George couldn't play what he came up with at tempo.
So, they slowed the tape way down and he played along.
Then, when the playback was at full speed, the sped up piano sounded somewhat like a harpsichord.
That's why it doesn't sound like a piano and still not quite a harpsichord.
Pretty clever!