According to Geoffrey Himes in 1989, the progressive soul movement of the early 1970s "expanded the musical and lyrical boundaries of [R&B] in ways that haven't been equaled since". This movement was led by soul singer-songwriter/producers such as Curtis Mayfield, Marvin Gaye, and Stevie Wonder. Norman Whitfield's productions at Motown, the record label of Gaye, were also pioneering for setting the soul vocals and simple hooks of earlier rhythm and blues records against strong backbeats, vocal harmonies, and orchestral sounds, all of which thickened the texture of the music. Gaye's own music on albums such as "What's Going On" (1971) incorporated jazz influences that led the genre into a looser musical direction.