Sumi Jo - Caccini - Ave Maria

And, it sounds as a 20th century piece, not 16th.

Read 'ecrowders' below and you will see it was composed in about 1970 by Vavilov and for some reason a hoax was perpetuated about it being Caccini's from many centuries ago. So you are right, it is 20th century.

The first time I heard Sumi Jo sing this, wsa in my car and it was the first time I heard the Ave Maria. I was transfixed and had to pull over to the side of the road to listen to it carefully.

Correct, 1970, but not a hoax: this is the way Vavilov signed and sometimes devoted his works. The Caccini's name was attached by him, not exactly as an author or a devotee though. We can only try to understand his motivation. Understanding the time and place, we can guess and probably feel why he did it this way. Again, this is one of the best performances performances ever.