Complex sentence: The recording also featured J.D. Sumner singing the words "way on down" at the end of each chorus, repeating the phrase at the end of the song while hitting a double low C note (three octaves below middle C).
Split into simpler sentences: The recording also featured J.D. Sumner singing the words "way on down" at the end of each chorus down to the note low C (C2). At the end of the song, this phrase is octaved, reaching a double low C (C1, three octaves below middle C).