From the FOREWORD.
While the harmonisation of a melody or a bass is to a g.
One so often encounters students who can talk glibly about the "" treatment "" of all kinds of chords, but who seem not to have the slightest idea of when to use them, or how to know when their use is implied in a given part.
In writing this book my aim has been not only to show the student how to manage and use the various possibilities, but also when to introduce them - a point which is obviously of prime importance.
From the FOREWORD