A frequently repeated—and just as frequently misattributed—quotation states that “talking about music is like dancing about architecture.”[1] For those of us who have at some point felt moved by a piece of instrumental music, the message rings true: what sense is there in talking about music when music is already perfectly capable of expressive communication? And yet, many of us find it difficult to resist sharing our excitement for a particularly moving or exciting passage or work, even when we struggle to convey that which our instincts tell us is ineffable. Some will tell you that studying music theory will empower you with the ability to truly understand music and thereby speak knowingly of its deepest mysteries. This is a dubious—perhaps even dangerous—claim. It will, however, provide you with core concepts and a tailored vocabulary, encouraging you to engage with music in a new way and discuss it with new precision. In this way, music theory will help you project an image of competence and professionalism.

There exists on our planet a staggering diversity of musical cultures, styles, and techniques. So great is this variety that what one person may identify and experience as music, another may perceive to be utterly un-musical. To come up with one musical theory, a reduction of this complex mosaic to a singular activity, would be to diminish a remarkable human achievement. This textbook, therefore, will not attempt to provide an account of the inner workings of all music. Instead, it will focus on one particular group of styles among many: tonal Western art music, a historical tradition which many listeners, performers, composers, and educators continually elect to make an important part of their lives. Even if the works and styles included here are rather limited in scope compared to the vast bodies of music that exist and have existed in the past, the ideas discussed in this book will give you valuable insights into other styles and traditions with which you may be more or less familiar.

Although often presented as such, the concepts discussed in music theory textbooks and classes are not rules or laws that govern how music works or how it should be written, performed, and heard. They are instead, as the name of the field implies, theories, derived from observations regarding certain trends and tendencies in compositional practice. In this sense, music theory as we will come to know it is a sort of hands-on music history, an activity that lets us experience for ourselves how—or at least how we think—historical practitioners heard and understood their art. It is important to keep in mind, then, that the characteristics we may encounter in one composition or style may not be found in another. As musical tastes varied from year to year and place to place, so too did the conventions around which musical ideas and expressions were formulated. It is also important to keep in mind that as creative human beings we are welcome to accept or reject the inclinations of our predecessors in our own artistic endeavors. Outside of our pursuit of historical understanding, we should not become overly attached to any particular rule and should instead remain both curious and open minded.


This book is organized into four parts. In the first of these we will describe how the rudimentary materials of tonal Western art music are organized and structured. These topics, though less theoretical than the rest of the book, will build a strong foundation and provide an essential vocabulary for the discussion that follows. We will begin by considering rhythm and meter, how musical sounds are arranged in time. From there we move to matters of pitch—the relative “highness” or “lowness” of musical tones. We will discuss how pitches are arranged in scales, how scales project a sense of hierarchy among pitches in a key, and how different keys relate to one another.

Many practitioners of tonal Western art music consider diatonic polyphony—the simultaneous sounding of multiple independent melodies—to be the cornerstone of this particular tradition. In the second part of this book we will turn to discussing the ins and outs of how composers combine musical voices. Along the way we will elaborate on the various foundational concepts discussed earlier as it becomes necessary. These chapters will build to a discussion of functional harmony and the manner in which composers are able to convey a sense of narrative drama through musical sounds alone.

The ideas and examples discussed in the first two parts of this book will be, for the most part, limited to music that remains in a single key. Though pedagogically useful, such passages do not reflect the reality of most tonal music. Pieces that use only the pitches of a single key are, in fact, quite rare compared to those that do not. In the third part of this book we will turn our attention to the myriad ways composers hint at and move from key one to another. We will also discuss chromaticism, instances in which musical tones that are foreign to the key at hand are incorporated into melodies and harmonies of a passage. Here, we will expand our harmonic vocabulary to include names for a number of chromatic sonorities. We will observe how these entities function—or defy function!—and how they facilitate motion to unexpected and exciting musical destinations.

These discussions will culminate in the fourth part of this book: an introduction to the concept of musical form, the shape and structure of a composition and its constituent parts. Through form we will engage with the entirety of an artistic work: first and foremost the interaction of harmonic and thematic elements, but also such other musical dimensions as rhythm, meter, texture, and expression. Our discussions will initially address the hierarchical nature of various structures in tonal Western art music—how the smallest musical elements work together to form larger sections and even entire pieces—as well as the ways in which various composers exploit this. Our discussions will cover a variety of the most frequently discussed formal paradigms, beginning with short compositional models and building to larger and more complicated archetypes.

Open educational resource

This textbook is an open educational resource (OER). It contributes to the small-but-growing body of openly licensed material available to music students, joining projects such as Open Music Theory in liberating the collectively inherited tradition of music theory. It is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License and is therefore freely available to everyone without discrimination. Readers are welcome to copy and redistribute the material in any medium or format as well as remix, transform, and build upon it for non-commercial purposes so long as derivative versions of this work carry a compatible license. Source materials are available by downloading the XML version of the book with additional files (including notation files for all of the musical examples) at

Like most textbooks, this is a work in progress. Readers are encouraged to send comments, suggestions, ideas, and other feedback to A changelog may be found at the end of the book.

  1. For more information, see Garson O'Toole, "Writing About Music Is Like Dancing About Architecture," Quote Investigator, November 8, 2010, (Archived at


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Fundamentals, Function, and Form by Andre Mount is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

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