If neatness counts for you, don t count on Anne Rice s musical-ghost novel Violin. It is an eruption of the author s personal demons, as messy as the monster bursting from that poor fellow s chest in the movie Alien. Like Rice, the heroine Triana lives in New Orleans, mourns a dead young daughter and a drunken mother, and is subject to uncanny visions. A violin-virtuoso ghost named Stefan time-trips and globetrots with Triana, taunting her for her inability to play his Stradivarius--which echoes