Jack Halloran, 81, singer and choral director for "The Dean Martin Show." Born in Rock Rapids, Iowa, Halloran earned degrees in music from Morningside College in Sioux City, Iowa, and Northwestern University. He sang with a male quartet called the Cadets on several Chicago-based radio shows, including "The Breakfast Club With Don MacNeil." He later formed the Jack Halloran Quartet, which appeared on the television programs "Dave Garroway at Large" and "The Pat Buttram Show." Relocating to Hollywood, Halloran became a choral director for films, records and television, working with such entertainers as Roy Rogers, Pat Boone, Ray Charles, Bing Crosby, Frank Sinatra and Martin. He landed the job as choral director and arranger on the nine-year Martin show while working with the singer on his recording of "Volare." Halloran later organized the Jack Halloran Singers, which performed throughout Southern California. He was a former local president of the American Federation of Television and Radio Artists. On Friday in Lancaster of a stroke.