Harmony. The D-A centered oscillation continues, but the addition of B♭, and the strong melodic focus on G, bring in G-D as a countervailing harmony. Both harmonies operate at a distance (T₂ or T₇) from the C-G structural fifth in the melody. A discrepancy between the pitch level of the harmony and the melody is a persistent feature of this piece (and of Stravinsky’s music generally). That the interval of displacement in this piece is usually T₂ or T₇ gives rise to the larger (mostly diatonic) pitch-class collections.