It's made from the same chord structure as This Boy,
I think its a great song, has a very eery feel.I Like This Boy alot more, but just for the harmonies, and great bass line...Plus Lennons amazing solo vocal part.
Yes It Is is supposedly the sequel to This Boy but it's much better creatively, musically & artistically with great vocals by John & one of the Beatles finest moments during the early 60's.
The best thing is recently learning that George did not use a volume pedal (or wah-wah) to get the guitar fade-in sound.