Jonas Petter Berggren, born on March 21, 1967, in Gothenburg, Sweden, is a prominent Swedish musician, singer-songwriter, and record producer, widely recognized by his stage name, Joker. He is best known as a founding member of the internationally successful pop group Ace of Base, which he formed with his siblings Linn and Jenny Berggren, and Ulf Ekberg. Jonas began writing songs at a young age, showing an early passion for music that was nurtured by his father teaching him guitar.

Berggren played a crucial role in Ace of Base's success, writing many of their biggest hits, including "All That She Wants," "The Sign," and "Beautiful Life." His contributions extended beyond performing, as he also played guitar and keyboards for the band. In addition to his work with Ace of Base, Jonas has collaborated with other artists and bands, such as DJ Bobo, Army of Lovers, E-Type, and Meja. He also produced and composed for the album "Pride" by the Swedish pop group Yaki-Da in 1995.

Jonas Berggren owns a recording studio called The Barn, where he continues to create music. His personal life includes a marriage to Norwegian hairdresser Birthe Haugland in 2000, with whom he has four children: Julia, Gabriel, Amanda, and Molly. After divorcing Haugland, he married Rosa Patriksson in 2024. Despite the challenges he faced early in life, including being born with a cleft lip, Jonas has maintained a successful career in the music industry, contributing significantly to the pop genre and leaving a lasting impact with his work.