Gregorian Chant music has long been one of my favorite listening experiences. For me, the experience creates a level of peacefulness, and it removes the mind’s constant preoccupation with unconstructive thoughts.
If you allow it, I think one can derive abstract religious experience from this music, as well. I do not see it connected with any particular religion.
Since the music focuses on a relative few number of sounds, there is a feeling of almost hypnosis for me, personally.
On this recording, one hears the chants done with small groups of singers, or with just one or two.
Here are selections from this recording: