Temporarily clean and sober, the yoga-flexing Red Hot Chili Peppers drop the macho mook posturing and frat-boy yuks in an attempt to craft a masterpiece with producer Rick Rubin. Multi-layered keyboard and glockenspiel parts fill the space left by the guitars, and Flea, through meditation, has all but purged himself of the urge to thumb-pop bass lines. There are more musical ideas here than in any three previous Peppers albums. It's definitely their most mature work, but does anyone really want to hear a sophisticated Red Hot Chili Peppers? It should be interesting to see how the sensitive numbers play in tube socks.