Three Landmarks for Instant Guitar Harmony

This 8-page PDF lesson picks up where the Instant Harmony: Just Add Thirds video leaves off, providing three foolproof ways to quickly orient yourself and launch a double-stop harmonized line on the fly.

I'm considering doing a video lesson with live demonstrations of this technique. Please let me know if that would be helpful!

Three landmarks for instant guitar harmony

In my Instant Harmony: Just Add Thirds YouTube video, I shared three ways to use a basic knowledge of the major scale to create harmonized lines: using parallel thirds, spread thirds, and sixths. If you haven’t seen that video yet, I recommend watching it before diving into this lesson. The rest of this will make a lot more sense if you’re familiar with the basic approach.

Although the method described in the video is relatively easy to use on its own, it can be challenging to integrate it into an improvised solo on the fly. One of the potential hurdles is doing the mental math to figure out which scale degree your finger is on while you are playing. This lesson will give you three foolproof approaches that you’ll be able to use on demand with almost no thought.

All of these approaches allow you to create harmonized lines while focusing your attention almost entirely on one string, which I think is a big win.

Approach 1: Half-step anchor points

The first approach takes advantage of the inherent structure of the major scale. There are only two places in the major scale where half-step intervals occur: between scale degrees 3 and 4 and between scale degrees 7 and 1. Finding a half-step interval inside a scale doesn’t fully determine where you are in the scale, but it does give you enough information to be able to play a harmonized fill.

As shown in the Instant Harmony video, the major scale contains major thirds built on the 1st, 4th, and 5th scale degrees and minor thirds built on scale degrees 2, 3, 6, and 7.

If we put these two facts together, it means that when you see a half-step interval in any major scale (or mode) fingering pattern, the upper note is either the 1st or 4th scale degree of the underlying major scale, so we can build a major third on top of it while staying inside the scale.

Even better, as we descend the scale from there, we know the next two scale degrees require minor thirds, and the one after that requires a major third. This gives us a neighborhood of four harmonized scale degrees that will work any time we see a half-step interval.

As an example, let’s look at the Dorian mode in pentatonic Form 1, as shown below. We can recognize this as the Dorian mode because it is built on a minor pentatonic scale, and the fill-in notes are over toward the bridge in the rectangle and up and toward the nut from the stack. If you’re not familiar with this breakdown, check out my Hidden in Plain Sight video.

There are five locations in this complete scale pattern with half-step intervals.

The top two strings are great places to start if you want to play a harmonized line in parallel sixths. Start by identifying the half-step interval. Then, visualize an inverted major third (a minor sixth) on the upper note of the pair:

With that anchor, we can build out two inverted minor thirds and a major third below that. Note the spacing of the notes on the high E string: there are always two whole-step intervals immediately below a half-step interval inside the major scale, so we get the same spacing below both the 1st and 4th scale degrees. Here, we happen to have started from the 4th scale degree, but we don’t need to know that to use this strategy.

We can do the exact same thing on the B string:

On the B string, we also have the option of building our thirds upward from the note we’re targeting:

We can also build spread thirds (as was demonstrated from “Blackbird” in the video) if we start on the A or D string:

In the context of an improvised solo, I think the inverted thirds (i.e., sixths) starting from the E or B strings are the most useful option from this approach, so I recommend practicing that the most.

To help reinforce the concept, here’s a version based on the C major scale. On the top two strings, we have two pairs of half-step intervals:

We can build inverted parallel thirds starting from the string pair on the high E string:

or from the B string:

Notice that in all of these examples, the pattern of target notes on the origin string and the order of major and minor intervals are always the same. We can’t go any further up or down the scale without knowing for certain which scale degree we started on, but this neighborhood of four parallel intervals is plenty for improvising a quick harmonized fill.

Approach 2: The naked whole step in the stack

When we use the Hidden in Plain Sight approach to turn a pentatonic stack into a major scale mode, there are three configurations that can occur, and each contains one string with no half-step intervals, which I hereby dub the “naked whole step”:

The lower note in the naked whole step is always the 5th scale degree of the major scale, and the upper note is always the 6th scale degree. This makes it easy to build harmonies that start there. In this location, we know exactly where we are in the scale, so if we want to, we can continue our harmonies for as far as the fretboard allows.

Let’s say we are playing either the Ionian/Aeolian stack like this:

Without even thinking about what key this is, we know that the naked whole step on the B string consists of the 5th and 6th scale degrees of an underlying major scale, so we can place a major third (or invert it to become a minor sixth) on the lower note, and a minor third (or major sixth) on the upper note.

If you keep track of where you are in the scale, you can use the method from the Instant harmony video to expand the pattern as far as you want up and down the fretboard.

This works exactly the same way for thirds:

Approach 3: Pin down the root

If you’re using the rectangle and stack approach to play a pentatonic scale, it’s easy to always know where the roots are. You just need to know whether you’re playing minor or major pentatonic to find them inside any rectangle or stack. If you also know which mode fits the chord progression you’re playing over, the root becomes an anchor for visualizing a harmonized line.

This is because each major scale mode corresponds to a particular scale degree of an underlying major scale:

The modes and scale degree of the root in the underlying major scale

So, if I’m playing the Mixolydian mode in Form 1, I know that the root corresponds to the 5th scale degree of the underlying major scale.

And I can build out a harmonized scale starting there:

Conclusion

All three of these approaches will take a little practice before they become second nature, but if you work at them, you’ll find it’s easier than ever to add harmonized lines into your improvised solos.