Ace of Base is a Swedish pop group that gained international fame in the early 1990s with their catchy, dance-pop sound. The original lineup consisted of siblings Jonas, Jenny, and Malin Berggren, along with their friend Ulf Ekberg. They achieved massive success with their debut album "Happy Nation" (released as "The Sign" in the U.S.), which included hits like "All That She Wants" and "The Sign." The group became one of the best-selling acts of the decade, celebrated for their infectious melodies and upbeat vibes. Over the years, Ace of Base has experienced changes in lineup but continues to have a lasting impact on pop music.