Swedish songwriter and music producer, called Joker, born March 14, 1976 in Norrköping.

He has co-written songs such as Invading My Mind and Papi for Jennifer Lopez, All Around the World and Heat of the Night for Paulina Rubio, Angels Ain't Listening for Basshunter, Coconut Tree and Maraca for Mohombi, Down for Whatever for Kelly Rowland, Everything Is Allowed and Parachute for Timomatic, Get Ready for Pitbull, Messin' Around and Move to Miami for Pitbull and Enrique Iglesias. No Lo Trates to Pitbull, Natti Natasha and Daddy Yankee.

Thörnfeldt has also written several songs for Melodifestivalen, such as Kadiatous One Touch'', Emil Assergård's Om allting skiter sig, Alvaro Estrella's Baila Baila, Tusses Voices and Eric Saade's Every Minute. He has also co-written Elena Tsagrinous' El Diablo, Cyprus' entry to the Eurovision Song Contest 2021.