"You'll find the chord in Debussy and Thelonious Monk – the tonic on top and the dominant on the bottom.
"[1] He has cited the music of Pérotin and other twelfth- and thirteenth-century composers as suggesting the technique of note augmentation used in Four Organs.
For performances of the piece, Reich recommended using electronic organs with as plain and simple a timbre as possible, without vibrato, to avoid the sound of the instrument itself distracting from the harmonic and rhythmic aspects of the piece.
"[5] A 1973 performance of Four Organs at Carnegie Hall in New York City nearly caused a riot, with "yells for the music to stop, mixed with applause to hasten the end of the piece.
"[6] One of the performers, Michael Tilson Thomas, recalls: "One woman walked down the aisle and repeatedly banged her head on the front of the stage, wailing 'Stop, stop, I confess.