Jonas Berggren, Swedish singer-songwriter, musician, and producer

Jonas Petter Berggren 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, which he is a founding member of, as well as for other artists. He is the oldest of the three Berggren siblings that originally made up 3/4 of Ace of Base, as well as the only male.

March 21 is the 80th day of the year in the Gregorian calendar; 285 days remain until the end of the year.