[3] Grüner-Hegge studied piano with Fridtjof Backer-Grøndahl, composition with Otto Winter-Hjelm and Gustav Fredrik Lange, and conducting with Felix Weingartner.

[2] When he made his debut as a conductor in 1927 in a piano concert with Elisabeth Reiss (1902–1970) and the Oslo Philharmonic, the composer Harald Sæverud wrote about him in Aftenposten: Odd Grüner-Hegge went about his task with an energy that eventually took the life of his baton, and it was perhaps fortunate that he was able to discharge part of the Coriolan Overture, with which the concert opened.

[7] Starting in 1931, Grüner-Hegge shared the position of chief conductor of the Oslo Philharmonic with Olav Kielland.

[2] Grüner-Hegge also appeared as a guest conductor in Budapest, Paris, the Hague, Hilversum, Copenhagen, Stockholm, and Gothenburg.

[3] Grüner-Hegge conducted works by young composers such as Geirr Tveitt,[8] Klaus Egge, Øistein Sommerfeldt, and Edvard Fliflet Bræin.