Well, the actual wording is something along the line of "unsigned recording artist" - so it doesn't mean a contestant can't have a musical career, just that they can't be signed to a label. At least, that was my understanding. There have been several previous contestants, Carrie Underwood most recently, that have even had recording experience (hers was in Nashville; her old website had several of her demos) but for whatever reason, were never picked up by a label...
So far, I'm most impressed with Taylor Hicks. He sang last night, was the guy who was prematurely going grey. Love his voice, even with the stage tics and mannerisms that seemed... off? Yeah.
Here's a link to some of his original stuff. Me likee! And, just for kicks, here's what he looks like without the grey:
He just might become my new TV boyfriend for the season...