The time in Leipzig is believed to have had a great influence on his musical development, and especially the organist Karl Straube (1873–1950) and conductor Arthur Nikisch (1855–1922).
He initiated the formation of Moss Orchestra Association in 1924 and served as conductor for a long series of years.
Perhaps his most popular work is the song Det lysnet i skogen with lyrics by Jørgen Moe.
[2] Islandsmoen was knighted by First Class of the Royal Norwegian Order of St. Olav and from 1952 received a Government artist salary.
Bagn Bygdesamling, a small museum on the home farm at Sør-Aurdal, created by Islandsmoen's brother Olaus, contains an exhibition of the composer's work.