Etymology/usage/grammar of rap rhythmic narrative

According to Crowe:

The history of rap is as eclectic as America itself. Its influences range from the tall tales of Chicago blues singers to the sing-song declarations of Mississippi riverboat men; from wild west folk songs to the intoned rhetoric of Martin Luther King and Muhammad Ali; from skipping rope rhymes and gospel to the syncopated rhythms of jazz, the pick 'n' mix culture of creole and even the lewder compositions of Cole Porter.

Still regarded as rap's essential ancestor, however, is the toast. Toasting is the African-American folk art of rhythmic narrative, a tradition probably passed down by nomadic African griots who would wander from village to village offering musical renditions of local history and mythology. Their early 20th-century American descendants told rhyming tales of exaggerated heroism, in which the black man, in contrast to his usual lot, won the day.

The story of rap follows the migration of these attitudes - mockery, self-preservation and pride - from the inner city to the commercial mainstream.

By the early 1970s, toasts were finding their way on to records. James Brown stole them wholesale, while Jalal Nuriddin's collective, the Last Poets, stuck theirs into pop songs. Radio DJs devised toast-like routines to segue songs, often rhyming well into the second verse. But it was the Caribbean-style sound systems, plugged illegally into the lampposts of the Bronx, that facilitated the development of what became rap. These tangles of wires and amplifiers invoked spontaneous street gatherings at which DJs and bystanders would rhyme to the beat.

It was at the so-called "block parties" of the late 1970s that hip hop's celebrated innovator, DJ Kool Herc, hung out. Formally known as Clive Campbell, the Jamaican-born Herc had one of the most powerful sound systems in the neighbourhood, with a funk and soul record collection to match.

The story goes that in a flash of inspiration Herc decided to put copies of the same record on to both turntables. By crossfading between decks he could play the best bit of the record - usually a percussive breakdown - for as long as he liked. In this way the breakbeat was born. And so were the B-boys, or breakdancers, who during this musical peak would spin their best moves."

For the complete article see: http://www.prospect-magazine.co.uk/Start.asp?accessible=yes&P_Article=12426