Music and Poetry of the Kesh by Ursula K. Le Guin & Todd Barton
It's a soundtrack from a coming future - a document of Kesh people. Wreathed with high detail arrangements which can take you through alien folk songs, synth ambience, self built instruments with impossible to falsify sound - both colourful and evocative.
Kesh were first presented in 1985 through Le Guin's book which was a story of Kesh woman and her tribe - deeply existential in its anthropological analysis. It came with detailed description and lots of elements to it that could help you understand the whole culture.
The material itself can be understood through the invented language which can bring you close to the likes of Anna Homler, Elisabeth Fraser and Meredith Monk.
A work of art to ponder and analyse.