My most astounding moment was listening a Russian mathematician turned musicologist chanting old primitive Gregorian hymns as it was supposed to be song before the Gregorian reform.
I missed the road accident by few inches because it put me in a trance and ectasy.😊
Some can with their voice induce modified consciousness as hypnosis.
It takes almost 9 minutes with a deep bass soloist voice to go out of the letter "A" of the word alleluia and the same for "A" in amen..
It was so different that what most people call gregorian singing that it is one of the greatest musical event in my life ...I discovered after that he used what is called "harmonic singing" voicing and overtone singing in the acoustic of Monastery to recreate gregorian hymns before the standardization of Saint Gregory the great.