Book excerpt: In this book Mike Perlowin combines the practical experience of being a working musician in the fields of rock, blues, country, R&B, reggae, and bluegrass with the theoretical knowledge of an academic background to explain music theory in terms that any moderately accomplished musician can understand. Starting with the most basic of lessons, Perlowin clearly and concisely explains the tonal relationships between notes and how they form different types of scales and chords. Instead of using examples from unfamiliar classical music, this book uses well known tunes like Mary had a Little Lamb or Silent Night to illustrate theoretical principles. Rather than offering information on how to play a specific instrument, this book is designed for people who already play proficiently but don't understand music's underlying theoretical principles. Although the book is relatively short, it contains the equivalent of a year's worth of college level material, all made accessible to the average musician desiring a better understanding of music theory.