Thaddis Laphonia "Kuk" Harrell is an American songwriter, vocal producer, arranger and engineer. He was a member of a songwriting–production team composed of himself, Christopher "Tricky" Stewart and Terius "The-Dream" Nash. In 2011, Kuk Harrell and partner Tricky Stewart joined the ranks of Fox's American Idol along with music mogul Jimmy Iovine, producing many of the songs performed on television by the contestants and released via iTunes. 2011 marked the highly anticipated return of Jennifer Lopez and her album LOVE? in which Kuk served as Album Vocal Producer. Earning his fourth Grammy for the vocal production of Rihanna's No. 1 Billboard Single "Only Girl ", Harrell is also the vocal producer and co-writer of Rihanna's Grammy-winning single "Umbrella". A composer and engineer on Beyoncé's chart topping "Single Ladies " from the album I Am... Sasha Fierce, he is also vocal producer and engineer of the Diane Warren-penned "I Was Here" from Beyoncé's 2011 album 4. He also produced the majority of the vocals on Mary J. Blige's Platinum album Growing Pains, which won the 2008 Grammy for Best Contemporary R&B Album. The first single from Growing Pains, "Just Fine", earned a Grammy nomination for best R&B vocal performance in 2007.

"Only Girl (In the World)" is a song by Barbadian singer Rihanna from her fifth album, Loud (2010). Serving as the album's lead single, it was released on September 10, 2010. Crystal Johnson wrote the song in collaboration with producers Stargate and Sandy Vee. Rihanna contacted Stargate before Loud's production and asked them to create lively, uptempo music. "Only Girl (In the World)" was the first song composed for the album, and the singer decided to include it on the track list before she recorded her vocals. Backed by strong bass and synthesizer, it is a dance-pop and Eurodance song that has an electronic composition. Its lyrics describe Rihanna demanding physical attention from her lover.