The AB Guide To Music Theory is intended to help people learning music to understand how music is written down, what the various signs and symbols denote, and what is meant by the common technical words used by musicians. Arising out of this, it provides an introduction to the basic elements in harmony and musical structure.

In the main, this book deals with the subjects of the Associated Board's theory syllabus for Grades 1-5. However, for the sake of continuity, the information has not been broken up to correspond with individual grades.