This is not a harmonica instruction book as some of the other reviews stated. This is a handbook badly in need of revision (1989). An example of a good harmonica instruction book is most anything by Gindick, Barrett, Portnoy, or Gelling (my favorite). The instruction book by Charlie McCoy is also worth a gander. Though this book has some useful tips on bending and overblows, it totally neglects to discuss how to do a blow bend, though there are several exercises for blow bending. Baker admits that overdraws are tough, and doesn't discuss or demonstrate them at all. Baker meanders through lots of different topics, but doesn't really teach much of anything.
The exercises could potentially be the best part of the book, but did the other reviews mention that they are not broken into separate tracks but the CD is simply a copy of the cassette tape as it was originally issued? That's right, the almost 60 exercises, totaling only 30 minutes, are on just 2 tracks on the CD, one for each side of the original cassette tape. Therefore, the exercises are practically useless, unless you are willing to re-record them broken into individual tracks. The publisher should have done this, or maybe Baker should have done this if he's still getting royalties, but the buyer shouldn't have to do it. By the way, the exercises are all in the back of the book and are not interleaved with the text; they're like an appendix, with virtually no explanations or tips. They are not as comprehensive as Barrett's exercises, and Portnoy's bending exercises are much better and cover more combinations. But Baker's exercises will give you some other things to try and they will most certainly humble you, especially when he plays fast.
There is nothing unique about this book and I definitely wouldn't recommend it to a beginner. But if you like owning different harmonica books, are looking for alternative explanations and are willing to divide the cassette-based CD into tracks so they can be used, then maybe you'll want to consider this book.