Tony Visconti once told me that even though he'd been making records for years, there were still so many things to learn. I know that feeling. As time goes by, various books have been stepping stones of knowledge. Mastering Audio was one of those books. Bob Katz runs Digital Domain, a highly-respected mastering studio and information resource (see www.digido.com), and he's also spent plenty of time engineering albums too. Despite its title, the book covers more than just mastering-it has solid guides on making better recordings, mixing, using compression and EQ, and such. Hard facts on digital audio make it a must-read for any professional engineer out there. Where else will you find this much information on jitter, clocking, sample rates, digital EQ, dynamic range manipulation, and more-delivered in a manner that doesn't bamboozle you with math or too much theory and grounded in the real world of making records? The appendices alone are worth more than most books; for example, there's an analysis of what happens to audio as it's broadcast from a radio station. One of the main thrusts of Mastering Audio is to examine the recent trend of super-loud CD mastering and explain why this is harmful to music (and listening) in general, which Bob does eloquently. He also campaigns for establishing monitoring standards for audio engineers in the same way there are standards for film mixing (good luck on that one). A very informative book. I've recommended it to many folks. Now I'm recommending it to you. ($39.99 list; www.focalpress.com)