The song is in the key of B and its lead melody spans two octaves. Inverted chords are used just as they are in other "Pet Sounds" compositions. Unlike other tracks on "Pet Sounds", which modulate their respective keys down a minor third, the brief key change in "I Know There's an Answers" ascends a minor third (on the lyric "now what can you tell them"). Granata identified the "aah, di-di-di-di-da" backing vocals and Love's "ba doo-be-doo-be-dooooo" vocal break as the album's "most striking bit of doo-wop".