The purpose of this study is to investigate the theoretical causes of the stylistic results of both compositions and spontaneous improvisations of jazz pianist and composer Thelonious Monk. The specific topics chosen for analysis include Klangfarben (sound colors), rhythmic displacement (the relocation or complete removal of expected rhythmic events), and economy of means (the judicious use of silence, simplicity, and economy). All of the above topics are addressed with regard to the composer's original works, his selected renditions of works by other composers, and his improvisations. The musical examples appear in transcription form, as some of them are unpublished. The topics are introduced in the first chapter, and individually addressed in subsequent chapters.