He moved to Oslo and studied modern composition at Norges Musikkhøgskole under Finn Mortensen and came in contact with major jazz profiles.
[1] In the late 1960s he started his own Ivar Antonsen Trio including Espen Rud (drums) and alternately Terje Venaas, Sture Janson and Bjørn Alterhaug on bass.
Here you can enjoy the hard swinging interaction with Thorgeir Stubø, Alex Riel (drums), Krister Andersson (tenor saxophone) and Jesper Lundgaard (double bass).
With residence in San Diego for 19 years, Antonsen had many interesting collaborations, including with Ravi Shankar's tabla player Abhiman Kaushal, drummer Duncan Moore, guitarist Peter Sprague, bassist Bob Magnusson and pianist Andy LaVerne on the album Dream Come True (2000).
He is highly respected among both European and American musicians and has played with jazz greats such as Jon Christensen, Palle Danielsson, John Surman, Arild Andersen, Ben Webster, Jimmy Heath, Slide Hampton, Art Farmer, and Karin Krog.