ACE OF BASE was a Swedish pop group, originally consisting of Ulf "Buddha" Ekberg and three siblings: Jonas "Joker" Berggren, Malin "Linn" Berggren and Jenny Berggren. The group released four studio albums between 1992 and 2002, which sold more than 30 million copies worldwide, making it the third-most successful Swedish band of all time, after ABBA and Roxette.
Happy Nation (reissued as The Sign) is one of the best-selling debut albums of all time, and was certified nine times platinum in the United States. It was the first debut album to produce three No. 1 singles on the Billboard Mainstream Top 40 chart: "All That She Wants", "The Sign" and "Don't Turn Around".
Following the formal departure of singer Linn in 2007, the band performed a series of concerts as a trio in Europe and Asia between 2007 and 2009. Jenny Berggren said in November 2009 that she would be taking an indefinite leave of absence from the band to focus on a solo career. In 2009, Jonas and Ulf recruited two new female vocalists, Clara Hagman and Julia Williamson, and released The Golden Ratio in September 2010.
Clara and Julia departed from the group in 2012, and in March 2015, the compilation album Hidden Gems featuring unreleased songs and B-sides from the group's inception through 2005 was released, with promotion for the album being handled solely by Jonas and Ulf.