Swedish musician, songwriter and producer, born July 20, 1951 in Döderhult in Kalmar County.

He belonged to the free theater group Fria Proteatern during the 70s. It was there that he became acquainted with the musician Anders Forsslund, and together with Mats Klingström they formed FJK in 1981. Jonasson Tolv was also a member of Höj Rösten.

FJK stopped producing new material in 1996 and thereafter Jonasson Tolv has worked together with a wide range of other artists, including Kjell Höglund, Christine Hellqvist, Mikael Samuelson and Maria Blom.

However, FJK has been reunited at regular intervals, during the summer they perform acclaimed concerts on the archipelago boat Blidösund.