Keri Lynn Hilson (born 1982) is an American recording artist signed to Zone 4, Mosley Music Group and Interscope Records. She is part of a collective of writers and producers known as The Clutch. Through the early and late 2000s, Hilson wrote songs for multiple rappers and singers, including Britney Spears and Ludacris. In 2007, she guest performed on Timbaland's hits "The Way I Are" and "Scream" and began a solo singing career. Hilson has made cameos in music videos for Usher, Ne-Yo and Nelly, amongst others. Her debut album, In a Perfect World..., was released in early 2009, spawning singles "Energy", "Return the Favor", " "Turnin' Me On" and "Knock You Down". Keri Lynn Hilson was born in 1982 in Decatur, Georgia. During her adolescence, Hilson studied piano and singing, and she joined the girl group D'Signe when she was 14. She became a songwriter and backing vocalist while in high school, and she attended Emory University. "Knock You Down" is the fourth U.S. single from Keri Hilson's debut album, In a Perfect World.... The song features rapper Kanye West and R&B singer Ne-Yo. The music video for the song premiered on March 23, 2009, one day before.