f(x)

F(x) was a four-member (originally five-member) South Korean girl group formed by SM Entertainment and active from 2009 to 2016. The name is a play on the mathematical notation for function, with "f" signifying "flower" and "x" representing the female's double X chromosome. The group made their debut on September 1, 2009, with the release of a digital single "LA Ch Ta". The quartet consists of Victoria, Amber, Luna, and Krystal. Krystal was first spotted by SM Entertainment in 2000, which earned her a small role in a short segment of Shinhwa's "Wedding March" music video. Former member Sulli first debuted as a child actress in 2005 when she was selected to play young Princess Sun-Hwa in the SBS television drama, The Ballad of Seo-dong. In 2006, SM Entertainment recruited Luna after seeing her performing on SBS's television program, "Truth Game". In September 2007, SM Entertainment recruited Victoria Song. A month later, Amber was cast in an audition in Los Angeles, California. SM first released a teaser preview of the group via YouTube on August 24, introducing them as "Asia's Pop Dance Group." For five days, SM individually released information through news portals and posted pictures of each member on SM Town's official website, starting with Korean member Sulli on August 26, Taiwanese-American member Amber on August 27, Korean-American member Krystal on August 28, Korean member Luna on August 29, and lastly the Chinese member Victoria on August 30. On September 1, the group's first single "LA Cha TA" was digitally released. Following their first performance at the Samseong-dong Fashion Center on September 2, the music video was screened and released online the next day. The group's first broadcast performance of "La Cha Ta" was held at MBC's music show Show! Music Core on September 5. On October 7, the group also released the electro-pop version of the digital single, "Chocolate Love", alongside their label mate Girls' Generation. The single was released for the promotion of the 4th edition Blacklabel series of the LG Cyon phone, LG Chocolate (BL40). On November 9, f(x) released their first single album "Chu". On May 4, f(x) released their first mini-album "Nu Abo". The lead single "Nu Abo" topped the online music portal charts Monkey3, Dosirak, and Bugs. The song also made it to the Gaon Chart weekly number-one singles. The music video for the song was released on May 6. The group made their live comebacks on KBS's Music Bank on May 7, MBC's Music Core on May 8 and SBS's Inkigayo on May 9. On July 17, the group started performing their next promotional single, "Mr. Boogie".They had their first performance of the song on MBC's Music Core. It was announced by SM Entertainment that Amber returned from the USA after a long leave since June 2010 and that f(x) is planning to release a studio album in February 2011. f(x) finally released their first album "Pinnochio" on April 20, 2011. The album's lead single "Danger" immediately went to #1 and stayed at the top of various online charts such as Melon. On April 29, f(x) received their first K-chart award on Music Bank. Their acclaimed second studio album, Pink Tape (2013), was the only K-pop album on US music channel Fuse's "41 Best Albums of 2013", the only idol album to be featured in Korean critics' definitive list of "Top 100 Classic Albums of All Time", and was named "Greatest K-pop Album of the 2010s" by Billboard chart. The group's third album, Red Light (2014) was commercially successful and well received by music critics. On July 22, 2015, f(x) released a Japanese physical single album, Summer Special Pinocchio / Hot Summer, which debuted at #23 on Oricon's weekly chart. In August, it was announced that Sulli had officially left the group to focus on acting. The remaining four members continued as a group, releasing their fourth studio album, 4 Walls, in October. Following the release of the SM Station single "All Mine" in 2016, the group halted group promotions and the members have embarked on individual music, acting, and modeling careers. In August 2019, f(x) officially reunited as a three-piece (without Victoria) and performed at the three-night SM Town Live 2019 in Tokyo concert. Former member Sulli passed away on October 14, 2019, former member Sull passed away from suicide. In the following year 2020, 4 of the remaining members left SM Entertainment to pursue new career endeavors.