Johannes Brahms (1833-1897) was motivated by the virtuosity of Richard M#westeur061#hlfeld (1856~1907), a clarinetist of Meiningen orchestra, completing four masterpieces in the chamber music for clarinet in his late years. The works including Trio for clarinet, cello and piano, op.114, Quintet for clarinet, two violins, viola and cello, op.115, and Sonatas for clarinet and piano, op. 120 no.1 &; no.2 are not only important masterpieces in the chamber music but also important repertoire for clarinetist,

This supporting paper is divided to four chapters: preface, Brahms’s life instruction, form and analysis, and interpretation of Sonata for clarinet and piano op.120 no.1.