What to read after On Studying Singing?

"Logical, clear, convincing, and, in my modest judgment, dead right." — Virgil Thomson, New York Herald Tribune
"I recommend this volume highly." — Maggie Teyte, Saturday Review
"One of the most sensible books on the subject of vocal art." — Felix Borowski, Chicago Sun-Times
This book is an invaluable guide for the student, parent, teacher, coach, or any person connected with vocalism. It is not intended to teach the student how to sing since no book could possibly do this. Its main purpose is to help him find a way to study singing intelligently.
The author, who is a member of the faculty of the Juilliard School of Music and a prominent musician with a vast experience of teaching singers, explains in this book clearly and logically just what a student can and cannot expect from singing lessons. He also discusses in detail the various subsidiary studies necessary to the singer, such as the study of musical notation and theory, ear training, languages, and other allied subjects.
Particularly useful and interesting is the section dealing with various methods employed in teaching vocal technique. In this section, Mr. Kagen debunks the so-called "scientific methods" of voice teaching and the concept of "building voices" — follies which have often led to an enormous waste of money, time, and effort.