Jonas Petter Berggren (born 21 March 1967) is a Swedish musician, singer-songwriter, and record producer, also known as Joker.

Jonas Petter Berggren was the first child of three siblings; his younger sisters are Linn and Jenny.

Jonas was born with a cleft lip, undergoing three surgeries within his first year.

[1] A founding member of Ace of Base, Berggren has written all of their biggest hits, including "All That She Wants", "The Sign", and "Beautiful Life".

[3] Berggren produced and composed for the album Pride by Swedish pop group Yaki-Da in 1995.