In the period 1953–59, he had a series of bands with local musicians, many to be influential on the Norwegian and some on the World jazz scenes, like the jazz singer Karin Krog (1955–56), the saxophone players Totti Bergh (1955–59), Bjørn Johansen (1956–58) and Harald Bergersen (1959), and drummer Ole Jacob Hansen (1959), most of whom later would play central roles in the renowned Kjell Karlsens Big Band that he started together with saxophone player Mikkel Flagstad (1959–64).
featured musicians like trombonist Frode Thingnæs, bassist Erik Amundsen and the singers Grynet Molvig, Laila Dalseth, Odd Børre and Kirsti Sparboe among others.
Karlsen also was the composer of the song of the popular figure Titten Tei (1972), a wooden dummy from the Norwegian children's television given life by Birgit Strøm.
[citation needed] Karlsen founded the record label Viking Music in 1962, and among the signed bands and artists were The Beatniks, Rannie Rommen, Lorne Lesley and Jack Dailey.
[2] In the summer of 2011, Karlsen was 80 years old and was celebrated with an anniversary gala at Oslo Konserthus where a large number of artist friends and partners lined up with a Big Band and choir for a musical event constituting a party out of the ordinary.