Mark IV was an American harmony vocal soul group, active primarily in the 1970s. Notable for their smooth, polished sound, the quartet is best remembered for their 1973 hit single, "Signs of a Dying Love." The band consisted of members Otis Smith, Jimmy Ponder, Earl Nelson, and Kenny Sinclair. Despite their limited discography, Mark IV's unique fusion of R&B and soul left a subtle yet enduring imprint on the American music scene of the 70s.