Lien Internet Archive: https://archive.org/details/LesStructuresSonoresLasryBaschetdownloadLaguMp3.com
Lien Youtube: https://www.youtube.com/watch?v=awaFd6gArLg
Lien Piped: https://piped.video/watch?v=awaFd6gArLg
Here’s a documentary (in French) about Les Structures Sonores, the experimental music group behind the soundtracks of The Web Planet and Galaxy 4.
This is my favorite soundtrack from the whole series. The glass pipe instrument sounds like absolute magic to me.