Bay Area vocalist Di'Jonn Grizzell, known as Jonn Hart, broke into mainstream R&B radio in 2012 with a chiming, booming, and raunchy number titled "Who Booty," an introduction to a sound he called "R&Bay slap." A remix featuring a verse from rapper French Montana extended the song's life on the airwaves. By the end of the year, the song peaked at number 25 on Billboard's Hot R&B/Hip-Hop chart. After that, Hart went independent with the Cool Kids Cartel label and released multiple installments in the Heart 2 Hart and Cool Kid Cartel Collection series of mixtapes and EPs. Hart also continued to crank out bass-heavy, club-oriented singles like "Papi," "Back That Azz Up," and "Trippin." ~ Andy Kellman