Throughout the 1950s, he played in the Karl Otto Hoff Trio, Eilif Holm Quartet and released an album with Mikkel Flagstad in 1956.
Amundsen performed on recordings with Karin Krog, Bernt Anker Steen, Erik Andresen, Laila Dalseth, Magni Wentzel, Bjørn Johansen, Jan Berger and Bjarne Nerem.
He played regularly at the Metropol Jazz Centre in Oslo, including with visiting musicians such as Bud Powell.
[3] Amundsen also played with Al Cohn and Bengt Hallberg, within bands led by Per Borthen and Totti Bergh, and the groups VSOBOP, Street Swingers, Storeslem and Jazz A Pell Oktett.
A selection of nearly forty tracks from his recording career can be heard on the album Portrait of a norwegian jazz artist (2005).