Asking some veteran members of this forum I noticed that Harmonic played a role of a distributor for French and German library companies in the UK.
Then I decided to make my inquiry public to get more information and listen to others' opinions.
So far, I know that foreign labels like Sonimage, PSI and Musical Touch Sound from France and Selected Sound from Germany were distributed by Harmonic.

Do you know any other French or German labels involved in this promotion process in Britain?

Second, did they promote all albums released by Selected Sound and Sonimage and etc... or were they selective in distributing the albums and they just picked up the ones which seemed more successful ?

Then, when did Harmonic liquidate and fold the company?
1990? 1985? or 1980? or ...

Last but not least, does anyone know the category number of their first album and last album they have released as Harmonic albums?

I just know that "CBL 676 Synth's And Saints - 1977" with the category number CBL 676 can be one of their last albums.
Do they have an album with category number 677 or 678?

I hope someone sheds some more light on this case.