ROACH may announce himself as being from Edinburgh, Scotland, these days but the voice he does it in remains the cumulative product of generations of Virginians, raised mostly in the church but not above a little off-the-books private enterprise. It's a voice that lends almost unshakeable authority to the songs Roach sings, although Granddaddy, for one, also rings true because Roach researchers know that his grandfather really did operate an illicit liquor trade and his own personal, small-scale mint.