Johannes Brahms is the most famous composer of 19th century Europe, and along with J.S. Bach and L. v. Beethoven, is one of the trio of Germany 3B’s. In 1891 Brahms heard clarinetist Richard Mühlfeld’s performance of a C. M. v. Weber’s concerto, and began composing a number of now famous works for the clarinet for Mühlfeld, including J. Brahms’s Sonata for Clarinet and Piano, op. 120, no. 2, which remains a classic clarinet piece to this day. The first section of this paper discusses Brahms’ life and the background which inspired the creation of J. Brahms’s Sonata for Clarinet and Piano, op. 120, no. 2. The second through fourth sections consider the various movements’ musical forms, tonality, rhythm, speed and other elements, deploying musical analysis to explain how to interpret the works in depth.