CAGED-Interval System

CAGED System
Fretboard
Reachable Octave Shapes
CAGED Interval
Author

CAGEDify

Published

May 27, 2025

This article explores how to effectively memorize the guitar fretboard by leveraging the CAGED-Interval System.

Quick Read

  • The CAGED system is a widely used method in guitar theory that helps players navigate the fretboard using five basic major chord shapes: C, A, G, E, and D.
  • It enables guitarists to visualize chord shapes and scales across the neck, and applies to major scales, pentatonic scales, and arpeggios, making it useful for lead playing and improvisation.
  • Criticisms of the system include its limitations for speed playing, its oversimplification of complex chords and scales, and reduced usefulness for advanced theory or extended arpeggios.
  • The CAGED-Interval System builds on the original by introducing two primary “reachable” octave shapes, simplifying interval thinking and adding flexibility.
  • This interval-based approach enhances navigation of modal scales and complex harmonic elements by focusing on interval relationships rather than memorized shapes.
  • The system is also adaptable to other instruments tuned in 4ths, such as bass and ukulele, helping players visualize chord tones, arpeggios, and scale positions.

CAGED System Definitions and General Opinion (as of 2025)

Guitar theory has evolved over time, but the CAGED system remains one of the most popular methods for learning fretboard navigation. It’s based on five major chord shapes that form a repeatable framework across the neck. By moving these shapes up and down the fretboard, guitarists can build chords with any root. The CAGED system helps map out chord tones and scales, extending a player’s understanding beyond the open position and removing the need for a capo.

General Opinions on the CAGED System

The CAGED system has long been a popular tool for learning the guitar fretboard, and for good reason. Many guitarists appreciate it as a foundational framework that helps them visualize chords, scales, and arpeggios across the neck. By associating musical concepts with five familiar open chord shapes, the system offers a structured and intuitive way to break free from the first few frets and explore the entire fretboard.

Strengths

  • Visual clarity: CAGED provides a consistent way to connect chord shapes and scale patterns to specific root positions, which is especially helpful for beginners and visual learners.
  • Fretboard navigation: It gives players a roadmap for moving through the fretboard in a way that feels musical, supporting rhythm playing, improvisation, and songwriting.
  • Transposability: Once a player understands a shape in one key, it can be moved up or down the neck to apply in other keys without needing to relearn fingerings.

Limitations

  • Not optimized for speed: Because CAGED positions use a mix of 2- and 3-notes per string, the system is not ideal for fast, fluid playing, especially for alternate picking or legato techniques common in rock, metal, or fusion.
  • Shape dependency: Some players become overly reliant on fixed patterns or “boxes,” which can limit musical phrasing and the ability to respond dynamically to harmony.
  • Limited support for advanced harmony: The system is best suited for major/minor harmony. It tends to fall short when applied to non-diatonic scales, modal playing, or complex chord extensions, unless additional theoretical knowledge is layered on top.

Despite its drawbacks, the CAGED system remains a valuable tool for many players. It provides a practical entry point to the fretboard, helping guitarists move beyond rote memorization and build a deeper understanding of musical structure.

Before we explore enhancements to the system, let’s take a closer look at how CAGED maps out chords, arpeggios, and scales across the neck.

Recap: CAGED System for Chords, Arpeggios, and Scales

Using the CAGED system, a C major triad can be mapped in five distinct positions based on five basic open chord shapes. These same positions can be expanded by adding nearby octave shapes to form arpeggios. From there, you can include the remaining scale tones (2, 4, 6, 7) to build major scales in five positions.



Intervals on the Fretboard – The Only Two “Reachable” Octave Shapes

Unlike the piano, where each note has a unique position, the guitar presents the same pitch in multiple locations, which complicates sight reading and fretboard navigation. On top of that, the five scale shapes of CAGED can feel inconsistent and hard to memorize.

However, when we examine octave intervals between root notes, we discover that only two octave shapes are ergonomically “reachable” (i.e., playable without shifting position). While other octave shapes exist, these two are the most practical and form the basis of the CAGED-Interval System.

These two shapes also apply to other instruments tuned in 4ths, like bass and ukulele. But due to the major third interval between the G and B strings on the guitar, slight adjustments are required when crossing these strings.


By stacking and linking these octave shapes, guitarists can build complete scale positions. For example, the following graphic shows how the Dorian mode can be constructed from these octave shapes.

From a playing perspective:
- If your 3rd or 4th finger is fretting the root, use Octave Shape 1.
- If your 1st or 2nd finger is on the root, use Octave Shape 2.

These two shapes are the building blocks. Stacked vertically, they form segments of scale positions. Linked side by side, they explain the transitions between neighboring positions—this is the core innovation of the CAGED-Interval System.

CAGED-Interval System

Let’s now apply these octave shapes to deconstruct and rebuild the five positions of the C major scale using interval logic. This removes the “arbitrary” feeling of CAGED and grounds it in interval awareness.


Each CAGED position is defined by which strings the root notes lie on. For example, the C shape has roots on the B (2nd) and A (5th) strings and contains: - One full Octave Shape 1 - Two fragmented Octave Shape 2s

This understanding allows you to play any musical element (scale, chord, arpeggio) rooted at any point on the neck.

CAGED-Interval Shape Shape 1 Shape 2 Strings with Roots Suggested Alias
C shape 1 full 2 fragmented 2nd (B), 5th (A) B–A root shape
A shape 2 fragmented 1 full 5th (A), 3rd (G) A–G root shape
G shape 1 full 1 full + 1 fragmented 3rd (G), 1st & 6th (E) G–E root shape
E shape 1 full + 1 fragmented 1 full 1st & 6th (E), 4th (D) E–D root shape
D shape 2 fragmented 1 full 4th (D), 2nd (B) D–B root shape

CAGED-Interval vs. Traditional CAGED

Why complicate things with another layer?

Because the CAGED-Interval System offers a more accurate and flexible framework, especially when working with modal or non-diatonic harmony. For instance, say you’re in the G System and want to switch from C major to C Lydian (with a #4). With the interval system, you simply identify that the 7th fret on the B string is the #4. No need to remap the entire scale shape.


Revisiting Chords, Arpeggios, and Scales with Intervals

Chords

Below are the C major chord positions across the five CAGED-Interval systems. Each diagram is mapped by interval rather than shape, making it easier to construct variations.

To create an extended chord like C69, simply build from the C system and add the 6th and 9th intervals.

Arpeggios

Arpeggios benefit even more from interval-based thinking. Since you’re not restricted to what can be played simultaneously, you can freely include extensions and voice-leading paths.

C Major Triad

Cmaj7 Arpeggio

Scales

The Lydian scale is an excellent example of how interval awareness simplifies modal thinking. Below are the five CAGED-Interval shapes for C Lydian.

CAGED-Interval System for Other 4th-Tuned Instruments

Because the system is based on intervals and tuning relationships, it adapts well to other instruments like bass and ukulele.

  • On ukulele, the system simplifies chord-melody playing by ignoring the guitar’s low strings.
  • On bass, while chords are less emphasized, this system excels at mapping arpeggios, intervals, and scales, especially on 5-string models.

Summary: The Two-Step Method

To apply the CAGED-Interval System effectively:

  1. CAGED Step:
    Identify the string and fret of your target root. Choose the corresponding CAGED shape based on that string (C, A, G, E, D).

  2. Interval Step:
    Apply Octave Shape 1 or 2 to locate interval-based targets for scales, chords, or arpeggios.

John Mayer once described soloing as seeing “shapes, colors, geometry, and endless possibilities.”

With consistent use, the CAGED-Interval System gives you the tools to see the fretboard the same way.