5-2 · Three Pentatonics Hidden in the Major Scale

This lesson contains the single most useful thing I know about the modes: six of the seven are a pentatonic scale you already know, plus two extra color notes. Once you see it, the modes stop being seven separate things to memorize and become another small family of scales you can visualize with the rectangle and stack.

The three brightest modes (Lydian, Ionian, and Mixolydian) each contain a complete major pentatonic scale built on their tonal center. The three minor modes (Dorian, Aeolian, and Phrygian) each contain a complete minor pentatonic. Locrian is the exception: it shares four notes with the minor pentatonic, but its ♭5 means no pentatonic fits, and we'll patch that up later.

That means completing a major mode is just a matter of adding the 4 and the 7 (in whatever form the mode uses), and completing a minor mode means adding the 2 and the 6. The rectangle and stack will make the locations easy to see:

• Lydian: the #4 is one fret below the 5, and the 7 is one fret below the root.
• Ionian: the 7 stays where it was, and the natural 4 is one fret above the 3.
• Mixolydian: the 4 stays, and the ♭7 is one fret above the 6.
• Dorian: the 2 and 6 are one fret below the ♭3 and ♭7.
• Aeolian: the 2 stays, and the ♭6 is one fret above the 5.
• Phrygian: the ♭6 stays, and the ♭2 is one fret above the root.

Now, recall from 3-8 that each major pentatonic shares its notes and shapes with a minor pentatonic. The modes come in pairs the same way, and this is the heart of the whole system.

Possibly more than anything else I teach, this is the visualization I use almost every time I pick up a guitar. Notice that the brightness order is visible in the shapes themselves: the further the color notes sit toward the bridge (in the rectangle) or toward the upper strings (around the stack), the brighter the mode.

For Locrian, start from the Phrygian fingering and lower the 5. This gives you a modified rectangle and stack to practice. It's easy enough to remember how it's made that you shouldn't need diagrams.

Hearing the modes

To hear what each mode actually sounds like, set up a drone using a chord that matches it. Three first-inversion triads on the top three strings, with the root on the high E string, cover all seven modes. The major drone covers Lydian, Ionian, and Mixolydian, because all three share the same major pentatonic, and the drone's notes all sit inside it. Likewise, the minor drone covers Dorian, Aeolian, and Phrygian.

Exercise 5-1: Choose a tonal center and a mode, and set up the matching drone. Find a root anywhere on the fretboard, place a rectangle or stack on it, and practice adding the color notes for your mode. Play just the pentatonic for a while, then add the color notes, then try playing only the color notes and listen to how much they stand out — the #4 of Lydian and the ♭2 of Phrygian are dramatic; the 4 of Mixolydian barely registers. Run some simple melodic sequences through the shape, in groups of three or in thirds. Then switch the color notes to a different position and hear the mode change under your fingers.

Spend real time on this one. The pentatonic shapes are already familiar from Module 3; what's new is adding the color notes and hearing them inside each mode's harmonic context. Everything else in this module builds on exactly that.