He enrolled in violin studies at the Norwegian Academy of Music in 1927, and joined the boys' choir Olavsguttene in 1928 and Oslo Domkor in 1932.
[1] During the occupation of Norway by Nazi Germany he was arrested on 29 November 1943 and was imprisoned in Grini concentration camp until 23 December.
Grythe had played the viola in the Norwegian Broadcasting Corporation radio orchestra since 1937.
In 1951 he was appointed as conductor of the Norwegian Broadcasting Corporation boys' choir, founded in 1947.
He received silver and gold records,[1] the Spellemann Honorary Award in 1990,[3] and the Gammleng Prize in 1996.