So I mentioned last post that I find Edith Piaf's voice to be a bit freaky, and yet, believe it or not, my default association with La vie en rose comes from an even freakier source. [I'll wait while you sample the link.] That's one of the Virtual Singers from the Melody Assistant line of music notation software. In fact, the makers of this program post that sample to advertise the product. Since the first time I heard it, I haven't been able to get that sound out of my head. He/she also sings Strangers in the Night and even a bit of coloratura from a famous stranger of the night. There are more samples here. Truly, we live in a golden age of virtual singers.
When you combine the wonders of Melody Assistant/Virtual Singer (free-to-try shareware which is quite inexpensive, powerful, and freakily designed) with all the freely available midi-karaoke files out there then . . . well, you get endless potential for magical moments. At least, you do if you're me. Here are a few little performances I've staged with minimal effort: Exhibit A, Exhibit B, Exhibit C.
Gregg, that last one's for you.
[UPDATE: Synth-like voices ID'd in nature. See here and here.]