I remember last time on a VST which I found nice to play around with, don't remember the name, but it was a monk which sing when you push and move the mouse.
While I work on the code of my new X11/cairo toolkit, I give this a shoot.
I'm using the SFFormantModelBP from the faust physmodels.lib, and wrap a UI around so that it comes near to what I remember and have a lot of fun while moving the mouse around on it.

Then I adding midi support (modwheel for the vowel), so that it may become a tad more the fun.

HOOOHEEEHAAA, here you go:

https://github.com/brummer10/Xmonk.lv2