"The Little Girl I Once Knew"
From Art Rock Wiki
"The Little Girl I Once Knew" is a non-album single released by the Beach Boys on November 22, 1965.
It is pretty typical ornate pop for the Beach Boys of 1965, until the song just drops out completely. It does this several times throughout the recording.
Bands stopped for dramatic effect in concert but there is little precedent for the complete silence built into this song. It is the clearest indication yet that Brian Wilson was moving beyond pop song conventions to something more.
We could think of it as one of the pivotal moments in Art Pop.