He was a concertmaster in Aberdeen, then a professor of music in Helsinki, and finally became a student once again, in St Petersburg, Leipzig (with Adolph Brodsky), Berlin (with Adolf Becker), and Liège (with César Thomson).

In 1899 he was appointed conductor of the orchestra at the newly opened National Theatre in Kristiania,[2] a position he held for 30 years until his retirement in 1929.

Halvorsen's compositions were a development of the national romantic tradition exemplified by Edvard Grieg though written in a distinctive style marked by innovative orchestration.

His best known works today are the Bojarenes inntogsmarsj (Entry March of the Boyars) and Bergensiana, along with his Passacaglia and Sarabande, duos for violin and viola based on themes by George Frideric Handel.

In early 2016, librarians at the University of Toronto announced that they had located the manuscript score of his violin concerto, performed only three times in 1909 and considered lost.