Beethoven's apparent disregard for the technical challenges he presented musicians is well known. Yet he also developed close relationships with a number of musicians and may have been influenced by their advice when writing for their instruments. This work examines Beethoven's relationship with the clarinet. The book begins by studying the history of the clarinet to place in context the stage of development reached during the time Beethoven was writing his symphonies. It also traces the role the clarinet had played up to that point within the orchestra. It then focuses on the clarinettists known to have associated with Beethoven, before moving to an indepth study of the clarinet parts in the symphonies themselves. This examination highlights the changing role of the clarinet through the nine symphonies and refers to their suitability for the type of instrument existing at the time.