In his book The Technique of My Musical Language, French composer Olivier Messiaen describes the seven modes of limited transposition he used throughout his career. These modes aren’t beholden to the idea of tension and release so prevalent in the Germanic tradition of western classical music.

Triads, however, can be fashioned from these modes, and in this single by Penzias and Wilson, they can create some crunchy instrumental rock. As the title suggest, this track employs mode 4 in the verses and mode 6 in the chorus.