Singer/rapper Amber Liu started out as part of the K-Pop group f(x) before beginning to release solo material, much of which she recorded in English. Born Liu Yi-Yun in 1992 in L.A., she began her music career at the age of 16 when she participated in massive K-Pop brand SM Entertainment's 2008 global auditions in her home city. Chosen from thousands of hopefuls, she moved to Korea and spent a year training to become part of the highly regimented K-Pop industry before debuting in 2009 as one-fifth of the girl group f(x). In her seven years with the group, they released four studio albums, all of which went to number one in Korea; the band then went on hiatus while the members launched solo singing and acting careers. Liu appeared in the TV drama Entourage (a remake of the U.S. series of the same name) and released several singles and an EP, Beautiful, before switching to recording in English. Cast as the "tomboy" of the group, Liu continued, even after going solo, to style herself with an androgynous aesthetic, with which she felt most comfortable. In 2019 she left SM and signed with an American label Steel Wool. Singles such as "Ready for the Ride," "Numb," and "Hands Behind My Back" were featured on her debut English-language EP X. Released early in 2020, it had a strong '90s pop/R&B influence.