Well, I got ripped for starting a different thread (when there's no easy way to find long-buried threads), but one of the links in my post there goes to this.
Running with the Devil (vocals only) - YouTube
The point being that, if you could hear unedited (or miminally edited) vocals only (or maybe with just coustic guitar, Mr. Dylan), it would be easy to tell whether someone is a bad singer or not.