D'après cet article de Spin, c'est un hoax (je trouve la chanson sympathique).
http://www.spin.com/2011/09/blowfly-hip ... ird-uncle/ Citation:
The story Blowfly tells, however, is that he flat-out invented it. In 1965. With “Rap Dirty.” But “Rap Dirty” wasn’t released until 1980, and it’s clearly intended as a parody of the Sugarhill Gang’s 1979 song “Rapper’s Delight.” Though he’s claimed in interviews that he first recorded the song 15 years prior, no copies of this earlier pressing have been found. Furmanski’s film doesn’t question Blowfly’s self-mythologizing — Ice-T even supports the fib –and that might come off as charming if The Weird World Of Blowfly didn’t otherwise take such a leering, disconcerting, The Wrestler-like approach to the almost 70-year-oldperformer’s career.
s'il fallait trouver des anticipations du rap, je les chercherais plutôt chez Norman Withfield avec l'intro (et la thématique gansta avant l'heure) 1990 (en 1973) des Temptations ou des trucs comme Car Wash
https://www.youtube.com/watch?v=l3DLtVyMceo