NY: 218 Press, 1981. First edition. Oblong 8vo. Wrps., unpaginated (64pp.). Inscribed by the composer on the half-title page: "pour Henri [Chopin] 12.7.87". Prints Johnson's series of fifty-six scores, conceptual studies of symmetry in music made using a music typewriter. In his introduction, Johnson describes how "about 20 Symmetries were arranged for piano for four hands, which combined the aural and visual. Here projections of the drawings were shown to the audience while Philip Corner and I played our interpretations, allowing the audience to both see and hear." Slight age-toning to edges of wrappers, o/w Fine.