Metallica is arguable the biggest metal band in history, and it's easy to see why; in Death Magnetic, front-man Hetfield delivers intense, emotionally-releasing lyrics with blistering intensity and perfect execution, the guitar and bass riffs are some of the most complicated and well-executed ever written by any rocker, while Ulrich dishes out some pretty stunning drumming even after 30 years in the band. Metallica is still king, and have paired their perfect technical proficiency with some very sophisticated song-writing and energy that many 20-year-olds can't muster to deliver another jewel in their crown. The music is heavy, so be sure your kid is into that kind of thing (chances are, if they're asking you for this album, they are). The lyrics are clean, but deal with some alienation, grief and thoughts of suicide. Provided your child has his head in the right place, that shouldn't be an issue; Hetfield isn't encouraging violence. rather, he uses poetry to deal with the issues that we all face and presents them in subtle, meaningful ways.