Question: HPSCHD is a composition by which music theorist and writer?
Sentence (from "Joseph Schillinger"): Joseph Moiseyevich Schillinger (Russian: Иосиф Моисеевич Шиллингер, 31 August 1895 – 23 March 1943) was a composer, music theorist, and composition teacher who originated the Schillinger System of Musical Composition.
Relevant evidence: No