For my project I have decided to focus my study on the development of performance practices of solo clarinet repertoire from the 1900's to the presentday. More specifically, I am interested in how certain composers/clarinetists have utilized the musical potentials of the clarinet in the context of contemporary extended techniques. Given the fact that the solo clarinet literature has expanded so dramatically in the past decades, I studied the compositions of two specific composers: William O. Smith's Variants (1963) and Bruno Mantovani's Bug (1999). My set question is: how do Smith and Mantovani exploit and explore possibilities for the clarinet within their works? My hypothesis is that it is possible to find technical and expressive elements of particular interest for the clarinet, due to an innovative writing that is decidedly relevant to the new tendencies of contemporary music. The paper presents the following structure: the first two chapters deal with the clarinet repertoire developments and the technical innovations of performance practices throughout the 20th century. The following chapters are dedicated to the study of the two considered works. Finally, the conclusions of the project and the bibliography. I based my paper by carrying out a bibliographical research on historical sources and consulting documents, websites and analyzing the scores in light of my musical skills and my direct practical approach and knowledge pertaining to clarinet technique.