Easy Arpeggios with the rectangle and stack

The rectangle and stack aren't just for pentatonic scales and major scale modes. You can leverage a little bit of knowledge about how chords are constructed to make learning arpeggios much easier (or, at least, to require way less memorization) with the rectangle and stack. This will give you multiple ways to play your major and minor triad arpeggios all over the fretboard, and it's easy to extend it to other types of chords as well.

This is a video version of an early PDF lesson — the PDF is available above.

Easy arpeggios with the rectangle and stack

The rectangle and stack methodology is an easy way to play the pentatonic scale across the entire fretboard and the most efficient framework for visualizing six of the seven major scale modes. It is also a great framework for learning to play arpeggios across the fretboard.

Much like the Fret Science approach to scales and chords, the goal here is to learn a method for recreating arpeggios on the fly rather than memorizing dozens of patterns. Use this to train your brain. It is far more efficient in the long run to practice reconstructing arpeggio shapes from memory than it is to memorize them outright, even if it feels slower at first. To do this, we’ll combine the rectangle and stack with the same basic chord-construction knowledge used in the Cowboy Chord Superpowers video. After all, an arpeggio is just a chord played one note at a time.

The framework

In this lesson, we will see how each chord overlays on the corresponding pentatonic rectangle and stack. Then, we will leverage the connections between rectangles and stacks to play each arpeggio across the fretboard.

Each chord arpeggio will be based on either the major or minor pentatonic scale, depending on the triad underlying the chord. In this method, we will study the major and minor triad arpeggios and then modify them to create arpeggios for more complex chords.

We will start with a simple Major Triad arpeggio. The notes of the major triad are contained in the major pentatonic scale, and their pattern in the major stack is like a chevron pointing down and toward the nut:

Similarly, in the major pentatonic rectangle, the major triad notes form a chevron pointing down and toward the bridge:

In these diagrams, it is most important to remember the location of the root (which is the same as for the corresponding pentatonic rectangle and stack). For the major and minor triads, it is also worth memorizing the locations of the 3rd and 5th so that you can modify them to create related chord arpeggios.

The “magic” in the method comes when we move from shape to shape across the fretboard. Moving vertically on the fretboard, we alternate between rectangles and stacks. In standard tuning, we must remember to always be aware of the warp between the G and B strings. As you will recall, any part of a pattern that lies across this boundary is shifted over by one fret.

Using this approach within the five familiar pentatonic boxes yields exactly the same “in-position” arpeggio patterns that have been taught in guitar books for decades. I have written them all out here so that you can study them and understand how they work, but don’t memorize them! The goal is to learn the overlays on the rectangle and stack and be able to recreate them on the fly.

One advantage of this method is that you can start and end an arpeggio from any arbitrary string. Just visualize the nearest rectangle or stack by finding the nearest root and go from there. This is much easier than memorizing the full patterns of all arpeggio types.

Diagonal (octave) moves

In addition to these in-position fingerings, we can use diagonal connections to create three-octave arpeggio patterns. As a reminder, here is how stacks connect diagonally:

If we apply this diagonal pattern to the fretboard and add the major triad overlay, we get two main pathways, shown here for the C major triad:

This approach also works with rectangles:

And here are the two main pathways for the C major triad:

So that’s four three-octave arpeggio patterns based entirely on the rectangle and stack.

Minor triads

The same approach works with other types of arpeggios. A minor triad is contained by the minor pentatonic scale, so it falls nicely on the minor pentatonic stack and rectangle.

Here in the stack, the minor triads form a chevron pointing to the upper bridge-side corner:

The rectangle’s chevron points to the upper nut-side corner:

As with the major triad, by alternating these shapes vertically, we get the five traditional in-position fingerings for the minor triad arpeggio. Here is the result for Form 1 of the minor pentatonic scale. I’ll leave the other four forms as an exercise.

We can also apply these overlays to the diagonal pathways:

Diminished triad

The same approach works for the other triad types. A diminished triad is a minor triad with a flattened 5th, so we can start with the stack and rectangle for the minor triad and move the 5th down a fret:

Augmented triad

An augmented triad is a major triad with a raised 5th, so we can start with the major rectangle and stack and move the 5th up one fret:

Major seventh (maj7)

A major seventh chord adds a major seventh to a major triad. Since a major seventh is one semitone short of an octave, we can add a note one fret below the root:

Dominant seventh (7)

A dominant 7 chord adds a minor 7th to a major triad. Since the minor seventh is two semitones below the root, it is convenient to drop it to the next lower string in the stack:

Minor seventh (m7)

A minor 7th chord adds a minor 7th to a minor triad. Since the minor 7th note is already part of the minor pentatonic scale, this one is particularly easy:

Half-diminished (m7♭5)

The last type of diatonic 7th chord is a half-diminished chord, also called m7♭5. This includes a minor 7th and a flattened fifth, and we can build it around the minor pentatonic scale:

How to practice this

You will find some of these combinations are more natural to play than others, and there is a lot to practice here. My recommendation is to start by practicing the major and minor triads until you have their rectangle and stack patterns thoroughly memorized and can reliably connect them vertically and diagonally.

When you are ready to move on to other arpeggio types, choose one arpeggio each day and practice it all over the fretboard using both vertical and diagonal movement.

As an example of this, let’s say we wanted to practice E7 arpeggios.

First, recall the E7 chord overlaid on the major rectangle and stack:

Then, practice finding your E roots all over the fretboard. On a 22-fret guitar, there are 12 of them!

Now, pick any root on the fretboard. Let’s say we chose the E at the 9th fret of the G string. If your index finger is on the root, since we’re using the major rectangle and stack, you’ll be starting on a stack:

Extend the pattern vertically by alternating rectangles and stacks (as always, taking the warp into account):

Or extend it along the diagonal:

If our third or fourth finger had been at the 9th fret instead, we would have started with a dominant rectangle:

Extend it vertically by alternating rectangles and stacks:

And finally, practice extending it diagonally:

Don’t forget to practice playing these both ascending and descending!

As you saw, from just one starting note position, we can build out four viable arpeggio pathways. I don’t think it’s necessary to practice all of these variants to burn them into muscle memory, but try them all, find the ones that work well for you, and practice those all over the fretboard until you feel comfortable working them into your improvisations.

Happy arpeggiating!