Bert,

There are examples of which some might put into the rap classification such as the "jivin" of Fats Waller. One notable difference it seems to me is that rap is a constant harrangue, an angry shout which has little dimension. There are no sad or happy raps it seems to me but just angry ones. Even the exhortation to "put your hands together" is more of a stentorian command than an appeal to have fun. Don't know Billy Cotton and how that fits in.

When other forms of African-American expressions in music are examined, there are dimensions such as happy blues or funny Calypsos. Rap seems emotionally and musically limited in spite of the sampling of rerecorded music.

Frank