The Sounds Of Synanon / The Synanon Choir – The Prince Of Peace: A Rock-Jazz Cantata [1969] by request, FLAC limited time only

 

As discogs indicates, this group is a:

Group connected to the drug rehabilitation program.

Wikipedia entry here, where it's described as a cult and a typical one at that, with the usual child abuse, forcible confinement, ridiculous messianic leader and gradual descent into violence as the group believes it's above the law.  Amazing how common the story was and still is, and to this day there are countless such cults in existence all over the world I'm sure.

With LP Notes:

Rush released by Epic Records the soundtrack of the color television special "The'Prince of Peace" to coincide with the show's national premiere on the Metromedia Network on Sunday, June 8, 1969.

Unfortunately I would say the music is very straightforward jazz-rock composing, similar to the style in the 1960s of jazz operas.  Sample, Quiet Sky:

Note that the music was composed by someone called Greg Dykes.