In the years during the writing of The Craft of Musical Composition, and for the next few years afterwards, Hindemith was engaged in writing a solo sonata for each of the instruments of the orchestra. Muser states that this series of sonatas continues a definite policy of providing music for people who want to play music, and not merely to listen to it. The three sonatas for solo brass instruments and piano were written during this period. The sonatas, written for trumpet, horn, and trombone, were written in the following order: Sonata for Trumpet and Piano—1939; Sonata for Horn and Piano—1939; Sonata for Trombone and Piano—1941. These sonatas, being written rather closely together, should have certain stylistic characteristics in common, and there should also be certain features peculiar to each sonata. To study these sonatas and compare them with each other structurally and stylistically is the purpose of this work.