Jonas Petter Berggren (born 21 March 1967) is a Swedish musician, singer-songwriter, and record producer, also known as Joker. He started writing songs when he was seven and continues to write for the band Ace of Base, a group he formed with his two sisters Linn and Jenny. Berggren has written most of their hit songs including "All That She Wants", "The Sign", and "Beautiful Life".
