Book excerpt: Music Theory Handbook is a comprehensive, easy-to-follow guide to mastering music theory for different instruments, providing a ready reference to terminology, sight reading, ear training, directives, and sound. Charlie Leadon, a classical piano child prodigy, wrote the handbook at age ten to help others discover the stimulating, always interesting world of music theory. Learning music theory can improve coordination with the arts and other subjects. As the great philosopher, Plato, said: “I could teach philosophy, science, mathematics, and art, but most of all, I would teach music, for music is all of them.” Highlights of the handbook include a chapter on frequency and decibels, a complete dictionary of musical terms, a complete dictionary of musical directives, and a table of music mastery. In short, this handbook has it all! Whether you’re just getting started playing the piano or need a refresher as you continue your journey, you’ll find this handbook to be an essential resource.