This is a 1970s children’s book featuring a kind of hippie spy/hero who (may have) flown around on a magic cloud and had a base (?) in the Himalayas. He had an enemy called Jasper, who stole (all of the) music.
I heard this as an audio book on a cassette (where I recall a song with the words ‘Jasper, Jasper, where has all the music gone?’)
On further reflection I think it may have had a Scandinavian element to it…
I haven’t come across anything that sounds similar. There might be more success in trying to track the cassette back, looking at online pictures to see if your memory matches it with a design e.g. anything in the Story Teller series (for example).
I’ve had a look at the UKs ‘Jackanory’ output, and one episode was broadcast in 1973 called ‘The Village without Music’ read by Dudley Moore and written by Hans Andreus (a dutch author, rather than scandanavian, and also a musician). However I have not been able to find a full description of the story or if it was ever released on one of the BBC’s Jackanory cassettes or LPs
https://en.m.wikipedia.org/wiki/List_of_Jackanory_episodes
Hans Andreus did publish a few books in English, one if which was ‘Stilt Pedlar and Other Stories’, but no contents list or details seem available.