Take a look to this singing voice:
http://www.youtube.com/watch?v=csI4F6GxPUI
“Singing voice to which the voice is synthesized based on the voice of recorded man extremely in the round” … Even Folteshimo, the crescendo, and the vibrato are adequately expressed, and the vocal sound source of the cutting edge sung while changing how to sing and Coeshiti according to lyrics, too is VOCALOID 2.
Looks & sounds very interesting 
Maybe you can get some ideas… 