Jazz Form is a term used to describe the various styles of jazz music. BOP, which stands for 'BEBOP, ' is a style of jazz that originated in the 1940s and is characterized by fast tempos, complex chord progressions, and improvisation. BEBOP is a more modern style of jazz that emerged in the mid-1940s and is characterized by its use of complex harmonic structures, fast tempos, and improvisation. Both styles are considered to be important elements of the jazz form.