Buying a recording--particularly of the average opera, which requires more than one compact disc--is an investment of sorts; the big sets usually aren't cheap. If you walk into the classical music section of one of the better record stores, you'll be confronted with a wall of jewel-toned boxes of operatic recordings. How do you choose between them? The problem is particularly acute for newcomers, who may know that they want a particular opera, but know the names of only one or two performers. The record companies have put their trust in brand names (such as Pavarotti and Domingo), but unless you're already a major fan of one of these high-profile singers, you don't need to seek only the CDs on which they are featured if you shop with the aid of a good guide. The Metropolitan Guide to Recorded Opera is written by people dedicated to opera who listen to recordings with practiced and critical ears, and who know--and can either recommend or trash--almost every recording available of any given opera. The volume lists 150 operas in chronological order, with the oldest first, then provides a roundup recommendation at the end. Having a single authority/critic for each score offers a consistent viewpoint for that particular opera, and much of the writing is lively as well as informative. As a bonus, the text is studded with "favorite recordings" recommendations of various operatic luminaries. These starred recordings aren't listed or indexed, though, so finding them is a matter of serendipity. The only problem with The Metropolitan Guide to Recorded Opera is that it isn't entirely current. Because it was published in 1993, it doesn't contain reviews of recordings published since that time.