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Circle of thirds

In music theory, the circle of thirds, also known as the cycle of thirds, is a way of organizing pitches, and a musical tool that helps musicians remember and memorize the order of thirds in a scale, and hence the notes of the chords in those scales.

Version
v1 · 2026-09-28 · History
Domain-specific #
8460
Domain group
Arts & Aesthetic Practice
Origin domain
Music & Musicology
Subdomain
Music Theory → Music & Musicology

Core Idea

Circle of thirds is treated here as the recurring socialscienceshumanitiesarts identity summarized by this source-grounded definition: In music theory, the circle of thirds, also known as the cycle of thirds, is a way of organizing pitches, and a musical tool that helps musicians remember and memorize the order of thirds in a scale, and hence the notes of the chords in those scales. In music theory, the circle of thirds, also known as the cycle of thirds, is a way of organizing pitches, and a musical tool that helps musicians remember and memorize the order.

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The Skip-a-Note Circle

In music, some notes sound nice stacked together. The circle of thirds is a way to line up the notes of a scale by skipping every other one, like C, E, G. Going around that circle helps musicians remember which notes make chords.

The Chord-Building Circle

A scale is a set of notes in order, like C, D, E, F, G, A, B in the key of C. The circle of thirds is a way of arranging those notes by skipping every other one, which musicians call moving by thirds. In C, the order goes C, E, G, B, D, F, A, and then around again. Most chords are built by stacking notes this way, so the circle helps musicians remember which notes belong in the chords of a key. In other keys, the circle starts on a different note, but the pattern of skipping is the same.

Scale Ordered by Thirds

In music theory, the circle (or cycle) of thirds is a way of organizing pitches by the order of thirds in a scale rather than by the ascending scale steps. A third is the distance from one note to the note two steps up in the scale. Going by thirds gives the scale degrees in the order 1-3-5-7-2-4-6, which in C major is C-E-G-B-D-F-A. In another key the circle starts on a different note, but the order around the circle stays the same. Because most triads (three-note chords) are built by stacking thirds, this circle helps musicians memorize the notes of the chords in a scale. It is less well known and less versatile than the circle of fifths.

 

The circle of thirds, also called the cycle of thirds, is a music-theoretic way of organizing pitches and a mnemonic tool for remembering the order of thirds in a scale, and therefore the notes of the chords built within that scale. Instead of listing scale degrees in ascending order, it arranges them by successive thirds: 1-3-5-7-2-4-6. In C this yields C-E-G-B-D-F-A, and in other keys the starting note changes but the circular order is preserved. Because most triads are constructed by stacking thirds, any three consecutive members of the cycle spell a triad of the scale, which is why the cycle is inherently tied to chord construction. It is less widely known and less versatile than the circle of fifths, but serves a distinct purpose. What identifies it is specifically this ordering of scale pitches by thirds as an aid to recalling chord tones, not pitch organization in general.

Scope of Application

  • HistoryOrigins. Although certainly not the first to use it, a popular American jazz musician named John Coltrane often used a cycle composed of a sequence of major thirds for his unique key.

  • HistoryOrigins. Although the exact date when the term "circle of thirds" was coined is not known, the circle of thirds and the coltrane changes continue to be used in many jazz compositions.

  • HistoryOrigins. The concept of a "circle of thirds" is relatively new in the history of music.

  • HistoryOrigins. The circle of thirds is also mentioned in relation to tonal music, but more rarely, as it is not nearly as practical as compared to other music theory concepts.

  • Chord construction. In fact, by going progressively forward in the repeating 24 note sequence of the circle of thirds, many chords can be constructed.

Clarity

A clear use of Circle of thirds names the carrier, the operative relation, and the conditions under which the source treats the identity as present. The minimal definition is In music theory, the circle of thirds, also known as the cycle of thirds, is a way of organizing pitches, and a musical tool that helps musicians remember and memorize the order of thirds in a scale, and hence the notes.

Manages Complexity

Circle of thirds compresses multiple socialscienceshumanitiesarts details into a stable diagnostic relation. The source shows both the central mechanism—the circle of thirds is the circle of fifths' Major keys, preceded by each associated minor key.—and the practical consequence—the circle of thirds is also mentioned in relation to tonal music, but more rarely, as it is not nearly as practical as compared to other music theory concepts.

Abstract Reasoning

  1. Type the carrier. Identify the socialscienceshumanitiesarts entities to which the claim applies.
  2. State the relation. Use the source-grounded identity: In music theory, the circle of thirds, also known as the cycle of thirds, is a way of organizing pitches, and a musical tool that helps musicians remember and memorize the order of thirds in a scale, and hence the notes of the chords in those scales.
  3. Check operation and conditions.

Knowledge Transfer

Within the home domain. Knowledge about Circle of thirds transfers literally when a new case preserves the same carrier type, relation, and recognition test. Although certainly not the first to use it, a popular American jazz musician named John Coltrane often used a cycle composed of a sequence of major thirds for his unique key changes, hence the namesake for "Coltrane changes." His popularity during the 1960s and in the ensuing decades, brought a lot of attention to the augmented triads, and.

Neighborhood in Abstraction Space

Circle of thirds sits in a sparse region of the domain-specific corpus (86th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Music Theory Concepts & Notation (20 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08