Career
He participated in various bands connected to the jazz clubb "Club 7" in Oslo, from the mid-1970s, including "Kråbøl", "Lotus" and "Chipahua". He is also known from "Jon Eberson Group" (1980-1984), "Jazzpønkensemblet" (1982-1985) and "Oslo Rhythm & Blues Ensemble" (1986-1987). Holmsen is educated at the Norges Musikkhøgskole, and did composition studies with Gunnar Sønstevold and Major Sønstevold, now Professor of Music at the University of Agder (UiA).
In the 1970s he took part in jazz bands led by Terje Lie, Paul Weeden, Espen Rud and Ditlef Eckhoff.
In the 1980s, Holmsen was within Chipahua, Jon Eberson Group and Jazzpunkensemblet. He is the composer of several of Major Britt Andersen album releases, and productions of Folk er rare at Det Norske Teatret and Riksteatret.