Someone of my generation was spinning the latest from Barney & Friends for their newborn when lightning struck. "Man," this mamma said to herself. "I really hate this shit. Too bad junior doesn’t crash out to ‘Master of Puppets.’" Glockenspiels, vibraphones, harps and bells class up and mellow out familiar tunes like "Fade to Black," "And Justice For All" and "The Unforgiven." It’s a golden idea for aging rockers who won’t subject themselves to one more kiddie song. The arrangements are pleasant and familiar but might be weak tea if you’re yearning for the originals. Maybe it’s time junior learned to really headbang, anyway.