[1] Øien was educated at the "Nord-Norsk Musikkonservatorium" (1987–91), where he studied the music of Edvard Grieg while he played in bands such as "Stett", "Tutu" and "Corny Horns".

Øien participated in the NRK series "Ung norsk jazz" with a trio comprising Trond Sverre Hansen (drums) and Konrad Kaspersen (bass).

In 1996 he led the jam backing band at Moldejazz Festival, and moved to Oslo, and settled as one of the most used freelance pianists in the last half of the 20th century in the Norwegian capital.

Other cooperation was with Knut Værnes, Staffan William-Olsson's records Smile (1998) and Oak road boogaloo (2000), Alf Kjellman Project, Beady Belle and Trionic, Ole Jacob Hansen, Espen Lind's band, Espen Rud Sextett, awarded Spellemannprisen 1998 for the album Rudlende, Tine Asmundsen's "Lonely Woman", and Geir Lysne's "Listening Ensemble".

Here he performed with an elite team of Norwegian musicians, including Kåre Kolve, Ellen Andrea Wang and last but not the least Jarle Vespestad.