Hansen established himselves on the Oslo jazz scene first in Tore Sandnæs Big Band (1958), Mikkel Flagstad Quintet (1959), Bjørn Jacobsen Septet (1958–60), Arild Wikstrøm Quartet (1961) and within Kjell Karlsen's various ensembles including at Moldejazz (1962), Bjørn Johansen Quartet (1962).