The musical structure contains an ambiguous tonal center and non-diatonic chords. Musicologist Philip Lambert cites its "choral fantasy" section to contain complex key changes that elude the listener "for the entire experience—that in fact, the idea of 'key' has itself been challenged and subverted". According to musicologist Stephen Downes, this quality made the song innovative not just in pop music, but also for the Baroque style it is emulating. Another odd feature was the use of multiple vocal parts sung in counterpoint, a technique that is distinguished from the "oos" and "ahhs" style of vocals for which the Beach Boys are known. The song closes with perpetual rounds, a centuries-old technique that was highly unusual for pop music of the era.