Twelve-Tone Row

Physics: 12-tone technique (Schoenberg 1921): all 12 pitch classes used before repeating. 4 forms: Prime (P₀), Inversion (I₀), Retrograde (R₀), Retrograde-Inversion (RI₀). Each × 12 transpositions = 48 row forms. Matrix: row across top, I-forms down column; R and RI read backwards. Combinatoriality: hexachord of P₀ = pitch-class complement of I₅. Berg's Violin Concerto row (1935) contains triads and a whole-tone segment. Webern's rows often have internal symmetries (palindromes, self-inversions).