Today, we’ll explore how the two fundamental and reachable octave shapes can be stacked to form the five positions of the CAGED system.
Stacking Octave Shapes
In the previous post on the CAGED Interval System, we observed that within any reachable position (limited to 3–4 frets), we can always locate at least one of the two octave shapes. The rest of the shapes within that position may appear as full or fragmented versions of the alternate shape, depending on the available strings above or below.
Interestingly, if we limit ourselves to the first 12 frets—before the octave repeats—we can identify only five possible combinations of these octave shapes. (And imagine if you hadn’t known this article was about the CAGED system—you’d have discovered it anyway.)
Finding the C, A, G, E, D Chord Shapes
Between two neighboring octaves lie all intervals—from the minor second (1 semitone) to the major seventh (11 semitones). The major third and perfect fifth are among these intervals and can be found in the octave shapes. Even in the fragmented octave shapes, one or two of the intervals may present.
Continuing from our previous exercise, once we’ve located all the C roots using the two octave shapes, the next task is to find the E (major 3rd) and G (perfect 5th) intervals. With this information—and a little creativity in omitting or rearranging tones—you’ll find yourself building all five positions of the C major chord.
The Two Pillars of the CAGED System
Comparing these stacked octave shapes with common open chord forms reveals a surprising result: the shapes align almost perfectly. That’s how the CAGED system was originally conceptualized.
CAGED is built on two core principles that simplify fretboard memorization:
Same shape, different root
Due to guitar tuning and string intervals, CAGED shapes are movable. You can shift a shape up or down the neck to play the same harmonic structure in any key.
Example: If you know a Cmaj7 shape, moving it up one fret gives you a Dbmaj7, two frets gives you Dmaj7, and so on.Same harmony, different shapes
The CAGED system gives you all the possible positions of the same chord or scale.
Example: There are five different positions to play a C major triad on the fretboard, each with its own voicing and ergonomic advantages.
Reframing the 5 Shapes
We’ve used root positions to anchor each CAGED shape. Each shape can be uniquely identified by which strings contain the root notes. While the C–A–G–E–D naming convention is based on open chord shapes, many find the names arbitrary since these chords are not harmonically related.
If we rename them based on root string locations, they become more intuitive:
| 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 |
What About Minor Chords?
CAGED is commonly used for major chords and scales, but it can also be extended to related structures—like maj7, 7, and sus chords—with ease.
However, minor chords and modal systems are often left out of CAGED discussions. Many approaches rely on the relative major scale, or diatonic relationships, to “backtrack” into minor chords. This can feel roundabout and limiting—especially for modal or jazz players.
The solution? Combine CAGED shapes with interval awareness. This unlocks the full potential of the system, allowing you to:
- Map minor scales directly
- Visualize modal frameworks
- Build extended and altered chords
Coming Up Next
In the following posts, we’ll explore how to: - Extend CAGED shapes to minor chords, modes, and exotic scales - Use interval mapping to analyze modal harmony and parallel modulation - Apply CAGED thinking to modern improvisation and chord-melody construction
More to come soon—don’t miss it!