Pure soul was popularized by Otis Redding and the other artists of Stax Records in Memphis, Tennessee. By the late 1960s, Atlantic recording artist Aretha Franklin had emerged as the most popular female soul star in the country. Also by this time, soul had splintered into several genres, influenced by psychedelic rock and other styles. The social and political ferment of the 1960s inspired artists like Marvin Gaye and Curtis Mayfield to release albums with hard-hitting social commentary, while another variety became more dance-oriented music, evolving into funk. Despite his previous affinity with politically and socially-charged lyrical themes, Gaye helped popularize sexual and romance-themed music and funk, while his 70s recordings, including "Let's Get It On" (1973) and "I Want You" (1976) helped develop the quiet storm sound and format. One of the most influential albums ever recorded, Sly & the Family Stone's "There's a Riot Goin' On" (1971) has been considered among the first and best examples of the matured version of funk music, after prototypical instances of the sound in the group's earlier work. Artists such as Gil Scott-Heron and The Last Poets practiced an eclectic blend of poetry, jazz-funk, and soul, featuring critical political and social commentary with afrocentric sentiment. Scott-Heron's Proto-rap work, including "The Revolution Will Not Be Televised" (1971) and "Winter in America" (1974), has had a considerable impact on later hip hop artists, while his unique sound with Brian Jackson influenced neo soul artists.