George Martin passed away this week. He is best known for being the man who signed and produced the Beatles (and for his pirate alter ego that wrote the Game of Thrones books).
He was immensely creative as a producer when the bag of tricks available to producers was limited. The harpsicord sound on this song (1:28) was achieved by playing a piano more slowly, then speeding up the tape to make it an octave higher.
I used to sing this song as a lullaby to my sons when they were little. I wasn’t good at impersonating a harpsicord, so I would impersonate a slowed down piano while running towards them very quickly.