Allegedly covered and sampled by musicians as diverse as Madonna and Diana Ross to Mary J. Blige and Robert Palmer, the innovative single “I Want You,” off Marvin Gaye’s 1976 album of the same name, branches out from the Motown sound that typified his earlier work and delves into uncharted territory. Recognizable instrumentation—the soaring strings, the hard-edged guitar, the smooth vocal harmonies—must have helped audiences to warm up to the strange new music that we, today, would categorize as disco. Lush, extravagant, atmospheric: the palette Gaye uses in this influential song turned a lot of heads and caught the ears of artists who would go on to make a big splash in the music scenes of later decades.