A professional from 1928, Hagerup joined Theaterkafeens orkester in Trondheim at age 17,[1] and played with various orchestras in Trondheim.[2] From 1934 he was based in Oslo, a member of Pete Iwers' orchestra,[2] also with engagements in Sweden, Finland, Denmark and Switzerland. He made his album debut in 1939,[1] and from 1939 was assigned with Øivind Bergh's orchestra, eventually as part of the Norwegian Radio Orchestra.[2]
His books include Trommeteknikk (volume I, 1944; volume II, 1962), and Trommeslageren from 1946.[1]
Hagerup died in Larvik on 4 July 1992.[2]
