Magnus attended school to study classical guitar when he was 10 years old. Later on he was very much into "The New Wave of British Heavy Metal" of bands such as Iron Maiden, Dio, Judas Priest and Black Sabbath. His influences as a guitarist were Steve Morse, Steve Vai and Allan Holdsworth. He has played in various metal and fusion bands early on and developed a style which mixes metal and folk music. His first critically acclaimed musical project was with the band Last Tribe, which has released three full-length albums. In 2004, Magnus started to work as a session musician in a project put together by Frontiers Records, which had the intention to have two acclaimed heavy metal vocalists singing together as a duet. The project ended up featuring powerhouse vocalists Russell Allen and Jørn Lande and was simply called Allen/Lande. The project released its first three albums with all music and the majority of lyrics written by Magnus Karlsson, featuring a variety of hard rock and heavy metal songs with a progressive metal touch. In the same year he also started to write music for a project with singer Tony Harnell, drummer John Macaluso and bassist Fabrizio Grossi that would later on become the band Starbreaker. In 2008, he worked with Magnum vocalist Bob Catley on his solo albumImmortal writing all the songs himself. The same year, Magnus joined German metal band Primal Fear making a big contribution to the band's songwriting. He also teamed up with the band's bassist and leader Mat Sinner to work in a number of projects released by Frontiers Records, such as Kiske/Somerville and the first solo album by Primal Fear frontman Ralf Scheepers. In 2013 it was announced that Magnus Karlsson would release his first solo musical project called Free Fall on 11 June in North America and 14 June in Europe by Frontiers Records. It features many guest singers who worked with Magnus before, including Russell Allen, Ralf Scheepers, Tony Harnell, Rickard Bengtsson, Mark Boals, Mike Andersson and other guests like David Readman, Rick Altzi and Herman Saming. Magnus also sings three tracks on the album himself and Daniel Flores recorded the drums. Magnus also wrote songs for the melodic hard rock project Place Vendome, 'My Guardian Angel' from the album Streets of Fire, 'Break Out' from the album Thunder in the Distance and 'Falling Star' from the album Close to the Sun. The second Free Fall album has been announced to be released in 2015. It's called Kingdom of Rock and features the following guests: Jørn Lande, Tony Martin, Joe Lynn Turner, Jakob Samuel, Harry Hess, Rebecca De La Moite, and once again Tony Harnell, Rick Altzi and David Readman, the last three also sang in the first album. Jaime Salazar recorded the drums. The album's release date is 6 November 2015. In 2017, it was announced another new project featuring songwriting, production and playing from Magnus Karlsson called The Ferrymen. The self-titled album also features drummer Mike Terrana and singer Ronnie Romero. In 2018, Magnus and Tony Harnell reunited to record the third album of Starbreaker which is titled Dysphoria and was released on January 25, 2019. It also features bassist Jonni Lightfoot and drummer Anders Köllerfors.
