Magnússon continued to study piano at the Reykjavik College of Music and graduated in 1949.
In 1954 he played his first concert with the Iceland Symphony Orchestra under conductor Olav Kielland and received rave reviews.
[2] Magnússon was very active in the Icelandic music scene and appeared in countless concerts, both live and on radio and television.
[3][4] Magnússon appeared in eighteen concerts as a solo pianist with the Iceland Symphony Orchestra in the years 1954 to 1989.
[1] Magnússon was the main external examiner for piano at the Reykjavik College of Music for the majority of his professional life.