How to read this table
  • Forte — catalog number (cardinality–index, e.g. 3–11).
  • Prime form — canonical label in parentheses; T = 10, E = 11.
  • ICV — interval-class vector (ic1 through ic6).
  • Sym — transpositional symmetry, inversional symmetry as two integers. Transpositional symmetry = number of Tn operations that map the set onto itself (always ≥ 1; T0 is always counted). Inversional symmetry = number of TnI operations that map the set onto itself (0 means none).
  • Complementary set classes are shown side by side; each row on the left pairs with the same-numbered row on the right.
Elevated symmetry (T-sym > 1 or I-sym > 0)
High symmetry (T-sym ≥ 3 or I-sym ≥ 3)
Z Z-related pair (same ICV, not T/I-equivalent)
Monads & Undecachords cardinality 1 ↔ 11 · 1 set class each
Monads (1 note)
FortePrime FormICVSym
1–1(0)00000012, 12
Undecachords (11 notes)
FortePrime FormICVSym
11–1(0123456789T)ttttt512, 12
Dyads & Decachords cardinality 2 ↔ 10 · 6 set classes each
Trichords & Nonachords cardinality 3 ↔ 9 · 12 set classes each
Tetrachords & Octachords cardinality 4 ↔ 8 · 29 set classes each (+ 6 Z-pairs)
Pentachords & Septachords cardinality 5 ↔ 7 · 38 set classes each (+ 2 Z-pairs)
Hexachords cardinality 6 · 50 set classes · 20 self-complementary · 15 Z-pairs

Music Theory IV — Spring 2026 — Dr. Avner Dorman

Set class data follows Forte (1973) with prime form algorithm per Straus (2016) / Rahn (1980). Symmetry: transpositional symmetry = |{n : TnS = S}|; inversional symmetry = |{n : TnIS = S}|.