This thesis is about jazz influence on classical clarinet repertoire, focusing on analysis and identification of all the jazz elements that run through this style into classical music. It also wants to describe the huge change of way of playing noticeable in the Swing Era in relation to the classical way.In the first part of the thesis I describe the birth of jazz and the political, historical and musical situation in the West, to understand the process in which they got blended. After that I identify and classify jazzy elements in classical music, analyzing in depth the repertoire of my exam-concert, which is strongly influenced by this style, and in a more superficial way other influenced classical clarinet works as well. I show in the very last part of the thesis how this influence is reflected, classifying these elements in harmonic, melodic, written and rhythmical ones.