South Korean vocal powerhouse Solji (born Heo Sol-ji) debuted as half of the two-piece 2NB before forging an internationally successful career as the leader of girl group EXID. In the 2020s, she began promoting as a soloist under C-JeS, issuing her debut mini-album, First Letter, in 2022. Born in Seoul's Gwanak district, singer Heo Sol-ji entered into the music industry as one-half of pop duo 2NB, having been scouted by Friday Entertainment in 2006. After debuting with the single "The First Fragrance" in March of that year, Solji went on to produce two albums in the pairing -- 2007's A Tearful Eye and 2009's 2comfortable -- as well as making her solo debut with individual tracks like "The Day I Loved" and "You Are Away from Me." Following several years of ballad-centric material under 2NB, Solji left the group in 2012 to pursue her career as a member of EXID ("Exceed in Dreaming"), a K-pop five-piece that had seen the departure of three of its members. Her EXID debut came with the group's 2012 debut mini-album, Hippity Hop, which charted at number 13 domestically. After a few subsequent singles including "Hey Boy" and "Up & Down," Solji was swiftly enlisted into the group's first sub-unit, Dasoni, which paired her with Hani for the 2013 single "Goodbye." Though "Up & Down" had failed to debut on the Gaon charts, a viral video of Hani performing the track transformed it into EXID's breakout hit. After success on social media and a showcase at the Ilchi Art Hall, the track rapidly climbed to the top of the Gaon, becoming the group's first number one single and leading to appearances on music shows like Show! Music Core and M Countdown. The group quickly found further show wins (Inkigayo, Show Champion) with follow-up single "Ah Yeah" (2015), which charted at number two on the Gaon and led to a number five chart debut for the group's second mini-album of the same name. During this time, Solji made her first solo competition appearance on MBC's King of Mask Singer, becoming the show's first winner and wowing judges and viewers alike with her impressive vocal abilities. In 2016, EXID issued their debut album, Street. The 12-track project, featuring the Solji solo track "3%," debuted at the number two spot on the Gaon charts. However, the project's success was soon overshadowed by medical issues: Solji's career was put on hold by a diagnosis of hyperthyroidism, which temporarily prevented her from promoting with the group. Though she was unable to participate in EXID's third mini-album, she offered vocal contributions to their fourth, 2017's Full Moon, while she continued to recover. In July 2018, she made a triumphant return to music to defend her crown on King of Mask Singer, and announced her return to EXID that September for the group's first Japanese promotions. However, while the promotions and subsequent debut Japanese-language album Trouble (2019) proved a success, the group soon entered a period of hiatus following their fifth mini-album, We. Gradually, all five of the group's members left its label, Banana Culture; Solji's departure came in February 2020, before she signed with C-JeS Entertainment to pursue a solo career. While recording for EXID's second Japanese album, B.L.E.S.S.E.D., Solji began promoting as a soloist, issuing the singles "Rains Again" and "Waste of Emotions" through the early 2020s. Her full-length solo debut came with the 2022 mini-album First Letter. Released on C-JeS, the set allowed the vocalist to demonstrate her impressive range across a series of ballads. ~ David Crone, Rovi