Cellist, singer, and beatboxer Kevin K.O. Olusola is best known as a member of the a cappella vocal ensemble Pentatonix. Born in Pasadena, California in 1988 to a Nigerian-born father and Grenadian-born mother, Olusola first began to play music at age four with piano lessons. At age six he started taking cello lessons, and at age ten added the saxophone. Throughout grade school and high school, Olusola was heavily involved with all the various school ensembles, from orchestra and concert band to marching band and jazz band. He also sought out several extracurricular musical activities, including playing principal saxophone with the United States Collegiate Wind Band's tour of Europe and winning a spot to perform at Carnegie Hall as part of the American Fine Arts Festival.

After high school, Olusola attended Yale, where he studied premed while also continuing to pursue his musical goals, including playing cello as a member of the Yale Symphony Orchestra. However, it was while on an overseas program studying in Beijing, China, that he developed his unique "celloboxing" technique, which involves, essentially, beatboxing rhythmic patterns while playing his cello. After returning to Yale, the technique helped win him the runner-up spot in competition presented by famed cellist Yo-Yo Ma. Inspired, Olusola began uploading YouTube videos of himself performing cover tunes in his distinctive celloboxing style.

In 2011, Olusola's video cover of cellist Mark Summer's "Julie-O" went viral and caught the attention of singer Scott Hoying, who invited Olusola to join his up-and-coming a cappella ensemble, Pentatonix. A week after graduating Yale, Olusola joined Pentatonix and auditioned for season three of NBC's reality vocal competition The Sing-Off. Pentatonix ultimately won the competition and signed a recording contract with Sony Music. Olusola has appeared on all of Pentatonix's albums including PTX, Vol. 1 (2012), PTXmas (2012), and PTX, Vol. 2 (2013), for which he co-wrote three songs. In 2015 Olusola released his debut solo EP, Renegade, which further showcased his unique classical, pop, hip-hop, and electronica-influenced mix of cello playing, beatboxing, and singing. ~ Matt Collar, Rovi