As the author of the introduction says, this is a good book, plain and simple. Bozeman writes as a life-long singer and teacher who has integrated vocology into his practice. The book's crowning achievement lies in Bozeman’s choice to keep the scope narrowly focused on acoustic registration. Given the generally agreed-upon shortcomings of current registration terminology, acquaintance with the concept of acoustical registration in itself is worth the read. Having personally wrestled with the concepts that Bozeman addresses for several years, I found his insights clarifying. I immediately put them into practice for myself and in my classroom with direct, measurable results. Every one of my singers have reflected on their ability to feel and understand the sensations associated with acoustical registration. He also does a nice job with the limited attention he gives to stylistic variants outside of bel canto singing, thereby including all learners in his exploration. His continuously updated website is a perfect companion to the book as well (www.kenbozeman.com). He, almost single-handedly, has brought acoustic registration theory into the 21st Century, and in such a beautifully approachable way. This is a must-have book for any singer's library.