Jack Sheldon, Trumpeter and ‘Schoolhouse Rock!’ Singer, Is Dead at 88

Jack Sheldon, an accomplished jazz trumpeter who also had a successful parallel career as an actor — but whose most widely heard work may have been as a vocalist on the animated television series “Schoolhouse Rock!” — died on Dec. 27. He was 88.

His death was announced by his manager and partner, Dianne Jimenez. She did not say where he died or specify the cause.

Jazz fans know Mr. Sheldon as a mainstay of the once-thriving West Coast scene and as a sideman with Stan Kenton, Benny Goodman and other bandleaders, as well as the leader of his own ensembles. Lovers of obscure TV shows might remember him as the star of the sitcom “Run, Buddy, Run,” the story of an innocent bystander who finds himself being pursued by gangsters, which lasted all of 13 episodes in the 1966-67 season.

And anyone who grew up learning about grammar, arithmetic and civics by watching the ingenious short musical cartoons known as “Schoolhouse Rock!” knows Mr. Sheldon’s voice, if not his name: He sang two of that series’ most memorable ditties, “Conjunction Junction” and “I’m Just a Bill.”