In the period 1979 to 1988, Knudsen played and produced the Theer Worst! (TAV!), Lions and Tigers and The Best . He released 5 LP’s and 3 singles, and got the 1980 Game Material Award for Material Fatigue with TAV! for 1980. His first solo album, La det brenne , was released in 2009. For the lyrics of his second album, We from 2017, he won the title of the author of the year under the Spellemann Prize 2017

He debuted as an author with the novel Brilliant Defeat in 1989. His 25th book Aaron’s machine came to Cappelen Damm in the fall of 2011 and received the Riksmålsprisen , nominated for the Critic Prize and the Brageprisen . He has also written the theater, the cloak and karri’s main event , and the singles Rytmeboksenand Gåkunstens decadence . He has written TV drama, for example the third character (NRK 2002) together with other writers. He has also been a writer for Hotel Caesar .

Knudsen has translated over 50 fictional books, including Charles BukowskiWilliam S. BurroughsNiall GriffithsNick CaveDouglas AdamsEdgar Rice Burroughs and Rudyard Kipling.

He has worked as a picolo, caretaker, distribution manager, consultant for publisher and film, carpenter, living room, teacher, driver, caretaker in Oslo Sporveier, salesman, documentation author in Norsk Data, copywriter at JBR reklamebyrå, Filadelfia advertising agency and multimedia developer (internet and CD -ROM) in HEP, BeatMap and AS. He started the digital communications agency AS in the fall of 1999, where he worked as a creative leader until 2001. He remained a full-time author and dramatist from 2002.