The tone of the author's discussion of the blues is______.

A．the attitudes of blacks and whites as reflected in their music are different
B．Beiderbecke's intellectualism held back his development as a musician
C．rebellion acted as a destructive force on Beiderbecke's performance
D．Armstrong was well established as a performer but Beiderbecke was not

A．Jazz places more emphasis on Afro-American culture than does the blues.
B．Jazz changes the attitudes of white musicians toward Afro-American culture.
C．Jazz is based on the blues attitude, but expressed in comprehensible manners to white musicians.
D．Jazz must be understood in order to be played, whereas the blues must be learned.