About Gain (singer)
Son Ga-in (손가인; born September 20, 1987), known mononymously as Gain, is a South Korean singer, actress and entertainer, best known as a member of the South Korean girl group Brown Eyed Girls. Having debuted with her home group earlier in 2006, Gain eventually made her solo debut in October 2010 with Step 2/4 to great commercial success, and has since released a total of six extended plays. In addition to her musical career, the singer also appeared in several native programs and series, most notably We Got Married and All My Love for You, where she co-starred alongside 2AM's Jo Kwon. == Career == === 2005–2009: Brown Eyed Girls and solo projects === Son Ga-In was noticed by the existing members of Brown Eyed Girls after she was eliminated during auditions for the popular South Korean reality series, Let's Coke Play! Battle Shinhwa! She was approached by composer Ahn Jung-hoon and invited to audition at Brown Eyed Girls' company, Nega Network, eventually joining the group. The four members performed several small shows before officially debuting as Brown Eyed Girls in 2006. In the same year, she performed a duet "Must Have Love" with SG Wannabe's leader Kim Yong-jun, which became her first number one hit during the Christmas season. Despite having initial successes, it was not until 2009 that her home group made a breakthrough into Korean mainstream with their hit song "Abracadabra", which was notable for the group's shift of their image and their new direction. After the unexpected success of the song, the group gained further recognition.
Biography source: Wikipedia. The profile adds birthday-specific historical context from the Celebs Birthday Today editorial database.