I'll go along with those Marion who say keep on singing unaccompanied. But also enjoy what seems to be some excellent accompianment when you want it. It would seem that you phrased your request very politely so I don't see a need to worry about stepping on people's toes. From the sounds of it the guitarist is an excellent player who accompanies rather than over playing. Likely then he is secure enough of his abilities not to be hurt by a singer who wants to sing a song or two alone.