Popular music is often concerned with matters of the heart, and during the '70s, songwriters found myriad ways to express their love through affecting ballads and euphoric pop. Stevie Wonder encapsulated the pure joy of infatuation with the upbeat “You Are the Sunshine of My Life”, while Marvin Gaye married his velvet-lined voice to steamy slinkiness on “Let's Get It On”. Whether it's the pure songbird vocals of Minnie Riperton (“Lovin' You”), the dizzying harmonies of the Bee Gees (“How Deep Is Your Love”) or David Bowie's triumphant wall of sound (“Heroes”), these artists prove love is more than a four-letter word.