IV: 1971, Extension of the Algebra of Poincaré Group Generators and Violation of P Invariance (Supersymmetry):

The origins of supersymmetry first appeared in this article by Gol’Fand and Likhtman. Supersymmetry is vital for calculations in string theory, but also helps solve irregularities in particle physics by supposing that for every particle is an anti-particle: a particle that is identical in mass and charge, but with a spin that differs by one half. The concept of symmetry pervades this movement. Every musical particle (melodic fragment, harmony, gesture) has its anti-particle, which is identical in all aspects but one. Melodies that rise in one instrument fall in another. Rhythms of one instrument are played identically by another, but backwards. A high chord in the piano is always answered by a low inversion of that same chord in the marimba.