Douglas "Jocko" Henderson ranks with Daddy O' Daylie and Hot Rod Hulbert as one of the original rhythm and blues radio disc jockeys. His smooth, swinging, rhymed talkovers were imitated by the jocks of the early rock and roll era, and became one of the major sources for the rap style. Though his influence on hip-hop was crucial, it took an indirect route as the model for the toasts of early Jamaican sound system deejays. Some say that Jocko's syndicated radio shows, beamed into the Caribbean from Miami provided the standard for Jamaican deejays. Another story claims that sound system promoter and record producer Coxsone Dodd encountered Jocko on one his record buying trips to the U.S., and encouraged his dee-jays to imitate Jocko's style. However his influence reached Jamaica, titles like "The Great Wuga Wuga" by Sir Lord Comic and "Ace from Space" by U. Roy were catch phrases directly appropriated from Jocko's bag of verbal tricks. When Kool DJ Herc adapted the Jamaican sound system to New York City party crowds, the stylized public address patter that accompanied his bass heavy program was rooted in Jocko's rhyming jive patter.
Jocko started in radio in the Baltimore of 1950, moving to Philadelphia, where he attained enough momentum to arrange a daily commute to New York for a second shift. It was in New York that he hosted "Jocko's Rocket Ship", a black oriented television dance party show that was the forerunner of "Soul Train". He also made many appearances as an M.C. of rhythm and blues shows and hosted large scale record hops that anticipated ballroom disco shows.
Jocko made few records, but we can thank the first wave of rap's popularity for an important recorded example what is arguably the original rap style. In 1979, in the wake of "Rapper's Delight", Philadelphia international released "Rhythm Talk", an instrumental track of McFadden and Whitehead's "Ain't No Stoppin' Us Now" over which Jocko ran through his amazing repertoire of oral formulas.