Simply because the next-to-latest entry in the thread was a relatively obscure Spanish piece, here's some 13th century Spanish court music that popped out of my memory banks.
I used to listen to it after particularly hectic deadline periods in a small warehouse (with an excellent stereo, it being a warehouse of musical CD's, etc.) Not a religious collection of songs [EDIT actually, they are religious songs, now that I check it out, have no idea how I had come to believe otherwise], but absolutely beautiful, including some poetry(?) read in a lovely female voice. The amazon samples give an "OK" impression of the CD, but they obviously can't capture the importance of pauses and quiet that frequently occur, nor the sometimes hypnotic quality of the full versions.
Now, I'll reluctantly post a video of extremely low quality, of a performance that I wouldn't want anyone to think of as representative of the recording mentioned above. Seriously, check the amazon link if interested, keeping in mind that the CD itself is of superb quality--a streaming sample could never register the clarity and intimacy of that disc, nor the beautiful flow of the selections as an "album". I only post this youtube vid in order to steer you away from even worse arrangements and performances that an admittedly more convenient youtube search would turn up.
Again, these people do a great job in my opinion, I mean no offense, but the Sonus CD is a completely different experience.