Jonas Petter Berggren (born 21 March 1967) is a Swedish musician and singer-songwriter and record producer, also known as Joker. He started writing songs when he was seven, and continues to write for the Swedish band Ace of Base, which he is a founding member of, as well as other bands. He was born in Gothenburg, Sweden. Jonas Petter Berggren was the first child of three siblings; his younger sisters are