Conversation so far:
how is the song hey jude composed?
The Beatles first taped 25 takes of the song at EMI's Abbey Road Studios in London over two nights.
how is the song structured?
Everett writes that the song's "most commented-on feature" is its considerable length, at 7:11.
what is an interesting feature regarding the structure of the song?
Hey Jude" begins with McCartney singing lead vocals and playing the piano.
The patterns he plays are based on three chords.

Question: what chords?
Self-contained rewrite: What chords are the three chords in Hey Jude based on?