Gerhard Kubik postulates that the harmonic development in bebop sprung from the blues, and other African-related tonal sensibilities, rather than twentieth century Western art music, as some have suggested. Kubik states: "Auditory inclinations were the African legacy in [Parker's] life, reconfirmed by the experience of the blues tonal system, a sound world at odds with the Western diatonic chord categories. Bebop musicians eliminated Western-style functional harmony in their music while retaining the strong central tonality of the blues as a basis for drawing upon various African matrices." Samuel Floyd states that blues were both the bedrock and propelling force of bebop, bringing about three main developments: