late breaking flurry of suggestions:
A. Parker with another goodie - weeping ceremonies on this ethnomusicological field recording Music of Oceania: the Kaluli of Papua Niugini
which you can get here
while we're on the ethno-exotico-voyeur tip, in the tradition of Missa Luba, and also My Life In the Bush of Ghosts, here's Gilles Aubry "performing" the glossolalia of charismatic churches in the Congolese capital Kinshasa. As suggested by E. Anderson.
another good one, from B. Cole - Filipe Pires
"Homo Sapiens - 1972
At the heart of this work is the human voice, used as the symbol of earth and creation. It is phonetically framed towards movement, elaboration, and the fusion of disparate sound elements. Homo Sapiens is a revision of the first part of the Nam Ban ballet, composed in 1970. The present version was composed while Filipe Pires was studying at the GRM in Paris."
see also "Canto Ecuménico", also using voices of ethnological provenance, on this recent Creel Pone reissue
S. Spiers-Conte materialises from the ghostly mists of memory to point out the startling omission of Bo Anders Persson
R. Rosengarde proffers
A. Thompson, with just a tinge of asperity, draws attention to the non-inclusion of the sound poems of Gil. J. Wolman, such as this, one of his mégapneumes
Two Swedes for the price of one (suggested by H. Blumner)
Another Swede - Ilmar Laaban - brought to my attention by J. Lyons
Did I not do Francois Dufrene already? M. Brewer thinks not. No harm in duplicating, I suppose
J. Maynard seems genuinely shocked by the omission of Karl Stockhausen's theatre of voices
Eerie-lovely choral music with serious hauntological pedigree - the theme tune to Children of The Stones, suggested by A-J. Kirby. You can hear the main theme right at the start but other outbursts of vocal strangeness crop up throughout the series, which is well worth watching in its entirety.
But who made the music? Revelation courtesy of A Sound Awareness:
"The music was composed by Sidney Sager who used a combination of a cappella vocalizations of a single, repeated Icelandic word ("Hadave") to create a terrifying and dissonant score. The vocals were provided by the Ambrosian Singers who during their long career have provided choral work for both Ennio Morricone and Nino Rota. he score for this series has never been commercially issued, which is a shame as both the "Start Title" and the "Ritual And End Title" are some of the scariest music I've heard on television."
And finally (?) - J. R. Press, points out an absolutely heinous absence - Yoko Ono