David Lewin showed that the T/I (“T-eye”) group is dual to a dihedral group acting on these objects whose three generators form orbits of size 2, 6, 8, and 24. Secondary operations like the Slide and Nebendverwandt (-5[1])act on these objects and can be written as products of P, R, and L. Leonhard (-5[1])Euler (10[1])visualized transformations on these objects (-5[1])with a hexagonal lattice diagram (-5[1])known as the Tonnetz that is studied (-5[1])in Neo-Riemannian (-5[3])theory. (10[3])A functional (-5[1])analysis of these objects (10[1])developed during the common (10[1]-5[1])practice period. These objects’ “quality” may be indicated with superscript (10[2])symbols like a triangle (10[1])or slashed circle. (10[1])Inversion changes (10[1])the voicings (10[1])of these objects, (10[2])whose “progressions” (10[3])are studied (10[1])in harmony. (10[9]-5[1])For 10 points, (10[3])name (10[1])these sets of (10[1])three or more (10[2])simultaneous (10[1])notes (10[3])that come in (10[2])“major” (10[1])and “minor” (10[1])forms. (10[1])■END■ (10[9])