Symmetry. Inversional symmetry is inherent in the array. Chord 6 is related to Chord 2 by inversion around A♯ as are Chords 5 and 3. Chord 4 is self-inversional around A♯ as is (trivially) Chord 1. (Chord 4 is also a subset of WT₀, and thus recalls the WT orientation of much of this movement.) This sense of symmetrical balance around A♯, however, is generally muted in Stravinsky’s registral arrangement of the chords.