Harry Tunney Waters Jr. (born April 13, 1953) is an American actor, singer and theatre director, best known for his portrayal of Marvin Berry in Back to the Future (1985). His renditions of "Night Train" and "Earth Angel" are two of the ten tracks on the gold record winning soundtrack album Back to the Future: Music from the Motion Picture Soundtrack. He created the role of Belize in the first production of Angels in America: A Gay Fantasia on National Themes in 1991. From Wikipedia
