Paul McCartney (credited to Lennon–McCartney).
Paul wrote it as an experiment. He asked his assistant, Alistair Taylor, to shout the opposite of whatever he sang to demonstrate how easy it is to create a tune. Beatles Song You Say Yes Say No
It explores the concept of duality —opposites like "yes" and "no," "high" and "low," and "hello" and "goodbye". Paul McCartney (credited to Lennon–McCartney)
The ending features an ad-libbed "Maori finale" where the band chants as the music fades. " "high" and "low
The song you're thinking of is by The Beatles. Released in November 1967, it became a massive #1 hit in the US and UK. Key Facts About the Song