His next symphony, the Third, earned a Pulitzer Prize, as did his Symphony No. 7. His Viola Concerto and String Quartet No. 5 also later received Critics' Circle awards. Piston was awarded the Edward MacDowell Medal for his outstanding contribution to the arts by the MacDowell Colony in 1974. Piston wrote four books on the technical aspects of music theory which are considered to be classics in their respective fields: "Principles of Harmonic Analysis", "Counterpoint", "Orchestration," and "Harmony". The last of these introduced for the first time in theoretical literature several important new concepts that Piston had developed in his approach to music theory, notably the concept of harmonic rhythm, and the secondary dominant. This work went through four editions in the author's lifetime, was translated into several languages, and (with changes and additions by Mark DeVoto) was still regarded as recently as 2009 as a standard harmony text. He died at his home in Belmont, Massachusetts on November 12, 1976. His library and desk are permanently exhibited in the Piston Room, at the Boston Public Library.