Thad Mumford (February 8, 1951 - September 6, 2018; full name Thaddeus Quincy Mumford) worked on Sesame Street in the 1970s, primarily as a songwriter. Usually working with Christopher Cerf, he wrote or co-wrote lyrics for songs such as "Oh, G (I Love That Letter)" and "Me Going to Munch You, Munch You, Munch You."
His most notable contribution was "The Ten Commandments of Health," in which he also voiced Dr. Thad, who was named after him. Every Body's Record also credits him as the voice of one of the Monotones in the song "With Every Beat of My Heart." Mumford also co-wrote the 1978 "personalized" Sesame Street book The Great Pigeon Race.
Mumford had a long career as a television writer (often with Daniel Wilcox) and producer. Prior to his Sesame work, he had already been associated with Children's Television Workshop as a staff writer and lyricist on The Electric Company (sharing in a collective Emmy Award for Outstanding Achievement in Children's Television).
Mumford also co-wrote the 1979 mini-series Roots: The Next Generation and wrote episodes for ALF, The Cosby Show, and M*A*S*H (including script contributions to the highly-watched series finale, "Goodbye, Farewell, and Amen.") He was also a producer in the later seasons of M*A*S*H, on ALF, and on the Cosby spin-off A Different World (for which he also wrote many episodes).