Interval Class Music Theory: Understanding the Building Blocks of Music

Music has the power to stir emotions, evoke memories, and take us on a journey through sound. But have you ever stopped to think about what makes music so powerful?

One of the key building blocks of music is intervals. In this article, we’ll explore what interval class music theory is and how it can help you understand and appreciate music on a deeper level.

What are Intervals?

In its simplest form, an interval is the distance between two notes. For example, if you play a C note on a piano and then play an E note, the interval between them is a third.

Intervals can be measured in terms of half-steps or whole-steps. A half-step is the smallest distance between two notes that are next to each other (e.g., C to C#), while a whole-step is twice as big as a half-step (e., C to D).

What is Interval Class Music Theory?

Interval class music theory takes intervals one step further by categorizing them into different classes based on their size and quality. This categorization helps us better understand how different intervals sound and how they can be used in music.

In interval class music theory, there are six basic classes of intervals:

Each class includes multiple specific intervals that fall within that category. For example, Class 2 includes both the minor second (e., C to C#) and the major seventh (e., C to B).

Why is Interval Class Music Theory Important?

By understanding interval class music theory, musicians and music lovers can gain a deeper appreciation for the complexity of music. When we listen to a piece of music, our brains are constantly processing intervals and recognizing patterns. Understanding interval class music theory can help us better understand why certain melodies or chords sound pleasing to our ears.

Interval class music theory can also be helpful when composing or arranging music. By understanding which intervals work well together and which ones clash, composers can create more interesting and dynamic pieces of music.


Interval class music theory may seem complex at first glance, but it’s simply a way of categorizing intervals based on their size and quality. By understanding interval classes, we can gain a deeper appreciation for the building blocks of music and how they work together to create beautiful melodies and harmonies. Whether you’re a musician or simply a lover of music, taking the time to understand interval class music theory will enhance your listening experience and give you a greater appreciation for the power of sound.