Berntsen founded the Svolvær folk song club Lovisa in 1968, and the Hamarøy music festival Troilltampen in 1973.
The album Ongan i Lofoten from 1982 contained songs for children, and was a cooperation with the Cirani orchestra.
His album I ly av Lofotveggen from 1984 contained self-written material, and also songs based on Petter Dass' poems "En smuk Aftensang" and "Den nordlandske torsk".
In 1986 he issued an album with texts for children, Lilla Bolla Bølla og andre boller.
Det e lys lenger frem was issued in 1976, and Sol bakom skyan was published in 1979.