Douglas "Jocko" Henderson, a slick-haired, silver-throated, legendary pioneer in Philadelphia and New York radio, died Saturday at the Hospital of the University of Pennsylvania after a lengthy battle with cancer and diabetes. He was 82 and lived in Germantown for many years.

Henderson, one of the first black disc jockeys in Philadelphia, was known for his rhythmic patter between songs. The trademark Jocko rap he sprouted at the beginning of his "Rocketship" radio show was so popular that kids recited it to keep time while jumping rope.

"Eee-tiddly-ock. This is the jock. And I'm back on the scene with the record machine, saying ooh-pop-a-doo, how do you do. . .?"

From 1952 to 1974, Jocko Henderson spun 45s and talked in rhymes on radio stations WHAT and WDAS in a style that was later copied by other deejays and has been called the forerunner of today's rap.

For many years, he commuted between Philadelphia and New York. He broadcast wildly popular radio shows in both cities and hosted R&B music reviews at the Apollo Theater in New York and at Town Hall and the Nixon, State and Uptown theaters in Philadelphia. He also hosted a TV dance show in New York.

Jocko's Rocketship show also was heard in Boston, St. Louis, Baltimore, Washington, D.C., Richmond, Va., Miami and Detroit. He was honored in 1993 with a brass plaque on the Philadelphia Music Alliance's Walk of Fame on South Broad Street.

Funeral arrangements were pending.