Set Class Music Theory is a branch of music theory that focuses on the relationships between collections of pitches, or “sets,” and how they are used in music. It is a complex and intricate area of study that has become increasingly popular in recent years among music theorists, composers, and performers.

What is a set?
A set is simply a group of pitches. In Set Class Music Theory, sets are usually represented using numbers that correspond to the number of pitches in the set and their interval content. For example, a three-note set with the intervals C-Eb-G would be represented as “3-1” (three notes with one semitone between each adjacent note).

What is set class?
Set Class refers to the classification of sets based on their interval content, regardless of their specific ordering or octave placement. For example, both C-Eb-G and Eb-G-C are members of the same set class (3-1), as they share the same intervallic content.

How does this relate to music?
Set Class Music Theory explores how composers use these sets in their compositions. Composers may use sets for melodic or harmonic purposes, such as creating a recurring theme or motif throughout a piece. Sets can also be used to create dissonance or tension in music.

The importance of pitch-class sets
Pitch-class sets are particularly important in Set Class Music Theory because they allow for analysis across different octaves and transpositions. A pitch-class set is simply a set that disregards octave placement, meaning that any note with the same name (i.e., all Cs) are considered equivalent. This allows for analysis that transcends specific key signatures or tonalities.

Common Set Classes

There are many different set classes used in Set Class Music Theory, but some are more common than others:

Applications of Set Class Music Theory

Set Class Music Theory has many practical applications in music composition and analysis. It allows composers to create unique and complex harmonies and melodies using sets, while also providing a framework for analyzing and understanding how those sets are used.


In conclusion, Set Class Music Theory is a fascinating area of study that provides valuable insights into how composers use sets of pitches in their compositions. By understanding the relationships between different sets, we can gain a deeper appreciation of the complexity and beauty of music.