The CAGED System and Triads Simplified

This was the 5th Fret Science YouTube video, uploaded on February 8, 2023. As of December 2025, it has received 296k views, making it my #5 video.

Original video description: This video deconstructs the CAGED system and presents it using easy-to-understand animated building blocks, starting with TRIADS, adding on PENTATONIC SCALES, and finishing with the MAJOR SCALE MODES. This is everything you need to unlock the fretboard and get started improvising.

To explore these shapes with any chord, the Voicing Finder — a Gold-tier tool — will hand you playable voicings anywhere on the neck.

The CAGED System (and Triads) Simplified

The CAGED system comes from the observation that there are five open-position major chords that can be turned into barre chords and moved around the fretboard. The name comes from the names of those chords: C-A-G-E-D.

To fully understand the CAGED system, you first need to understand triads.

A triad is made up of two stacked third intervals. A major third is a distance of four semitones/ frets, and a minor third is a distance of three semitones/frets. There are four ways these intervals can be combined to make triads, yielding four types of triads: major, minor, diminished, and augmented.

We can also construct a triad by picking three notes out of the major scale, skipping one note in between each one we choose. Extracted in this way, there are major triads built on the 1st, 4th, and 5th scale degrees, minor triads built on the 2nd, 3rd, and 6th scale degrees, and a diminished triad built on the 7th scale degree. There are no augmented triads in there.

The notes in a triad can be played in any order. When they are as close together as possible, that’s called “closed form”, and there are three possible orderings. If the root is on the bottom (1 - 3 - 5), we call that “root position”. With the root on top (3 - 5 - 1), we have first inversion, and with the root in the middle (5 - 1 - 3), we have second inversion.

There are nine closed-form triad shapes on the fretboard. Really, there are just three—one for each inversion—but the smaller interval between the G and B strings (the “warp”) distorts the shapes when they cross that invisible line (see next page for fingerings).

From major:

• To get minor, lower the third one fret
• To get augmented, raise the fifth one fret
• To get maj7, lower a root one fret
• To get dominant 7, lower a root two frets

From minor:

• To get major, raise the third one fret
• To get diminished, lower the fifth one fret
• To get m7, lower a root two frets

You can think of the CAGED system as being like a pegboard, where if you know the locations of the roots in any diagram, you can just snap that pattern on top of the roots. You just need to be aware of the “warp” between the G and B strings.

Along with the nine triad shapes, the most useful building blocks are the minor and major rectangle and stack. Note that the minor triad is fully contained in both the minor rectangle and minor stack. Similarly, the major triad is fully contained in the major rectangle and stack.

There are two useful ways to layer the major scale modes on top of this. First, you can complete 6 of the 7 modes by filling the missing two notes inside the rectangle.

Or you can use the repeating 5-string modal pattern. Just choose the scale degree that corresponds to the mode you want to play (1 = Ionian/Major, 2 = Dorian, 3 = Phrygian, 4 = Lydian, 5 = Mixolydian, 6 = Aeolian, 7 = Locrian). Treat the notes with those numbers as the root, and snap the pattern onto your imaginary CAGED pegboard. Just don’t forget to account for the warp between the G and B strings!

One of the biggest benefits of using the CAGED system in this way—layering root, then triad, then pentatonic scale, and then major scale mode—is that it provides a natural hierarchy of notes that you can use to organize your improvisations.

• Root: The root is home base. It’s the most important note on the fretboard.
• Triad: The notes of the triad are always consonant with the chord being played. They make great targets to end your phrases.
• Pentatonic: The pentatonic scale adds two notes to the triad, and these extra notes let you make melodies with your lines.
• Mode: A mode adds two notes to the pentatonic scale, giving you additional colors to compose with.

You’ll need to experiment to discover which scale tones you like best to provide different degrees of tension and release. Knowing where to find them under your fingers is the key enabler for that exploration…and that is the CAGED system.