Particularly remembered for his screenwriting and songwriting work on children's television shows and films, he made major contributions to both Sesame Street and The Land Before Time.
He studied at Cornell University and briefly served in the United States Navy.
He wrote the teleplay for a 1991 TV movie version of Beatrix Potter's The Tale of Peter Rabbit.
Born to Marjorie and Alexander Geiss, he spent his youth in New York City. He and his wife of six-decades, Phyllis Eisen, died just one year apart.
He was on the writing and production teams for the 1986 Steven Spielberg feature An American Tail.