Demo samples sound good...

http://www.bestservice.de/en/cantus.html

Also 

Altus, the Voice of Renaissance

http://www.bestservice.de/en/altus.html

AND

Chris Hein Winds Complete

http://www.bestservice.de...in_winds_complete.html
 

These all sound great.  Thanks

 Cool stuff Larry. If you're experimenting with vocal software, you should have a look/listen to vocaloid. I picked it up on sale a few weeks ago. I'm pretty amazed. The program has a piano roll view and you simply type the words in and she sings it.
 
There are many examples of her singing on you tube but I auditioned her for a whole part of a song just to see how practical it would be.
http://soundclick.com/share.cfm?id=12638755
 
I did her vocal part in a few hours without reading the manual, I'm actually pretty impressed how well it can articulate those fast lyrics...better than me. During the harmonies I think you will see it can be very useful. Instant female back-up vocals, just add lyrics.

Nice....

cclarry
Demo samples sound good...

http://www.bestservice.de/en/cantus.html

Doesn't sound, in the slightest, like any Gregorian Chant I ever heard. As for sounds, Very cool.

ohgrant
 Cool stuff Larry. If you're experimenting with vocal software, you should have a look/listen to vocaloid. I picked it up on sale a few weeks ago. I'm pretty amazed. The program has a piano roll view and you simply type the words in and she sings it.
 
There are many examples of her singing on you tube but I auditioned her for a whole part of a song just to see how practical it would be.
http://soundclick.com/share.cfm?id=12638755
 
I did her vocal part in a few hours without reading the manual, I'm actually pretty impressed how well it can articulate those fast lyrics...better than me. During the harmonies I think you will see it can be very useful. Instant female back-up vocals, just add lyrics.

Is this the one you got Grant? http://www.vocaloid.com/en/lineup/vocaloid3/ (Vocaloid 3?)

 
Which library(s) did you buy?

 No, this one, http://audiodeluxe.com/products/vocaloid3-megpoid-starter-pack  Still on sale at AD. I think it is currently the only one that English is supported.
 
No other Libraries so far