On his fourth album, John Michael Montgomery matures into a magnificent singer with nearly bottomless emotional resources, whether addressing his late father (''I Miss You a Little'') or venturing into Roy Orbison territory (''How Was I to Know''). But What I Do Best producer Csaba Petocz (engineer for Metallica, Stevie Nicks) never really lets him get wound up. It's like never driving a Ferrari over 40. B+

