The principal forms, P1 and I6, of Schoenberg'sPiano Piece, Op. 33a, tone row feature hexachordal combinatoriality and contains three perfect fifths each, which is the relation between P1 and I6 and a source of contrast between, "accumulations of 5ths", and, "generally more complex simultaneity". For example, group A consists of B–C–F–Bwhile the, "more blended", group B consists of A–C–D–F.center|400px (en)
