hear this guy

Listen to the cut Vox Humana from John Englemann here
http://artists.mp3s.com/artists/74/john_n_engelmann.html
There is some microtonal content in some of the other pieces also.

This choir is beautiful:
http://artists.mp3s.com/artists/83/markells_voices_choral_ems.html

A couple of pieces from this rock band feature throat singing
http://artists.mp3s.com/artists/6/big_sky.html

This is very interesting sound, and some of the tonal stuff is microtonal
http://artists.mp3s.com/artists/4/marc_mcnulty.html

Doing everything he can to make a standard guitar play micro
http://artists.mp3s.com/artists/27/philip_tomasic.html

John Starrett
"We have nothing to fear but the scary stuff."
http://www-math.cudenver.edu/~jstarret/microtone.html