Truman Nelson, a civil rights activist and New Yorker who had asked Reich to compose a sound collage that was separate from Come Out, gave him a collection of tapes with recorded voices to use as source material.
Nelson agreed to give Reich creative freedom with the tapes that he presented him for the sound collage.
[3] Reich eventually used the voice of Daniel Hamm, one of the boys involved in the riots but not responsible for the murder; he was nineteen at the time of the recording.
They quickly slip out of sync to produce a phase shifting effect, characteristic of Reich's early works.
Reich says in the liner notes of his album Early Works of using recorded speech as source material that "by not altering its pitch or timbre, one keeps the original emotional power that speech has while intensifying its melody and meaning through repetition and rhythm."