7-8 · Gear Shifts: Changing Scales Mid-Flight

Changing from one scale to another in the middle of a line, on purpose, and without stopping, is the capstone skill of this course. It's the sixth operation on the module map: switch.

When I first started trying to play over chord changes, every time the chord changed, I had to stop, find the new root, remember which shape went there, and basically start over. By the time I'd found it, the chord had often already changed again. With what you've learned in this course, you can now play more than a dozen scales anywhere on the neck. The remaining skill is moving between them while the music keeps going.

I have several lessons on the site that go deeper into this topic (search for "gear shifts" on the lessons page), so this section isn't the complete method. What I want to do here is show you the two most common kinds of shift, connect them to shapes you already know, and get you practicing them on their own and in combination.

Two kinds of shift

A gear shift is a scale change you make on purpose, in the middle of a line, without stopping, to a related scale. The word "related" matters. We're usually moving around inside a key, not jumping around at random. Every shift in this section changes the shapes under your hand a little, and the notes you're aiming at a lot.

There are two kinds of gear shift worth practicing. In the first, the root stays put and the scale around it changes, as when you go from minor pentatonic to major pentatonic over the same chord. In the second, the root moves, and most of the time your rectangles and stacks move with it to a different string set. That's what happens when you change scales to follow the chords.

The root stays put

You've already done the first kind a little. Back in 3-8, when we introduced the major pentatonic, I pointed out that if you keep the root fixed and switch between major and minor pentatonic, a stack becomes a rectangle and a rectangle becomes a stack. The root doesn't go anywhere.

So the shapes swap, the root holds still, and the notes you're aiming at change. That's one type of gear shift, and it's the most common one in blues and rock. Over the one chord in a blues, the major pentatonic and the minor pentatonic both work, but in different ways: the major pentatonic sounds sweet and settled, and the minor pentatonic sounds a little bit gritty. Many blues players go back and forth between them constantly, sometimes inside a single phrase.

You can make the switch right on a chord change, or you can anticipate it by a beat or so, which often sounds more musical. Don't forget to give that ♭3 a little bend when you're on the minor side over a major chord.

A great way to practice this is to play up and down the scales in one position and flip between them after every eight notes, while still always playing the next available note in the scale. I recommend visualizing rectangles and stacks as you do this, but if you've absorbed the five pentatonic forms, there's a nice shortcut: to go from minor to major on the same root, add one to the Form number. In the video, I was shifting between Form 1 and Form 2. The same rule works in every position, and Form 5 wraps around to Form 1.

The root moves

The second kind of shift is a bigger idea, and it's the one I want to spend most of this section on. Sometimes it's helpful to change to a scale that fits each chord as it goes by, instead of playing one scale over the whole progression. It makes your lines follow the harmony, and it's the approach a lot of jazz players use, although it works just as well in other genres.

It sounds like it would mean finding a new root and a new shape every time the chord changes. But you already know something that makes it much easier. Back in 5-2, we saw that six of the seven major-scale modes have a pentatonic scale hiding inside them. The three major modes, built on the one, the four, and the five, each contain a major pentatonic. The three minor modes, built on the two, the three, and the six, each contain a minor pentatonic. And those six pentatonics come in pairs: the six-minor and the one-major are the same notes, and so are the two-minor and the four-major, and the three-minor and the five-major. That's the relative major and minor pairing from 3-8. So inside any key, there are really only three pentatonic scales to think about, and each one covers two chords.

Here's where they sit. On any three adjacent strings, the minor roots form one column and the major roots form another one three frets higher:

Memorize this: Inside a key there are three neighboring pentatonic positions: home (the six-minor and the one-major), shifted up a string (the two-minor and the four-major), and shifted down a string (the three-minor and the five-major). Any rectangle or stack you're playing at home moves to the other two positions the same way, up a string or down a string, with the usual adjustment for the warp.

If you think in terms of the five forms, shifting up a string skips over one form and shifting down skips the other way. Here's what that looks like starting from Form 1:

Let's try it on a one, five, six-minor, four progression in D: D, A, Bm, G. The Bm and D pair is home. The A is the five, so that's shifted down. The G is the four, so that's shifted up. And between Bm and D, nothing moves but the root, because they're a relative minor and major pair. So the whole progression is home, down, home, up. Four chords, and you never have to find more than one note by name.

Same fingering, different hierarchy

Now here's the part I find really satisfying. Remember from 5-2 that you turn a pentatonic into a full mode by adding two color notes, and the color notes sit in one of three places: the upper position, the staggered position, or the lower position. The home pair, the six-minor and the one-major, take the staggered color notes. The shifted-up pair takes the upper position. The shifted-down pair takes the lower position. It's easy to remember: up is upper, down is lower.

And when you fill them all in, you get the exact same fingering three times. Because of course you do. They're all modes of the D major scale. So in terms of the notes, you haven't changed scales at all. What's changed is the hierarchy: which note is the root, which notes are the chord tones, and which notes are the color. That's what changes your lines, because that's what changes where you focus and where you land. It's why I'd much rather think "shift up a string" than "play the G Lydian mode." It may be the same notes, but it's completely different guidance for your hands.

The Andalusian move

Now let's combine these moves. Earlier in the module, we looked at the Andalusian cadence. In A minor, it goes Am, G, F, E.

We already know how to handle the first three chords. A minor is the six-minor, so that's home. G is the five, so that's shifted down. F is the four, so that's shifted up. It's the same three positions we just used in D, but this time in the key of C.

The E major chord is the new part. If it were E minor, it would be the three-minor, and it would live in the shifted-down position. It's still an E chord, so the shapes still go there. But the chord is major, and the minor pentatonic's ♭3 is a G. The chord wants a G♯. So the move onto the E chord is a root shift combined with an edit: your rectangles and stacks move to the shifted-down position, and then one note changes. Raise the ♭3, and the minor pentatonic becomes the dominant pentatonic from 3-9.

This is exactly why I had you think "Phrygian dominant" instead of "A harmonic minor" back in 7-5. When you shift to E and build the dominant pentatonic around it, the notes under your fingers are the root, 3, 5, and ♭7 of the E7 chord. The shift puts the chord tones right under your fingers.

In the video, I play straight eighth notes up and down the scales, changing scales in time with the chords using these shifts, first with the backing track and then without it. Even with the track gone, you can hear the chord changes in the line. And it's nothing but pentatonic scales.

How to practice this

When you're composing or improvising, the most important things are to know which scales are potential fits for each chord, to be able to see how the roots move, and to practice those shifts in isolation. So don't practice this over a whole song at first. You're combining several skills into one, so you'll need to develop each skill in isolation and then practice them in various combinations.

Exercise 7-12: Start with a one-chord backing track, like the A7 vamp below, and alternate: two bars of A major pentatonic, two bars of A minor pentatonic. Keep the root fixed and watch the rectangle and stack trade places. Then try switching every bar, then mid-phrase. I highly recommend doing this in straight quarter notes or eighth notes up and down the full scales in position, as I do in the video, as well as playing more natural phrases.

Exercise 7-13: Put on the I - V - vi - IV track in D below. Pick a position, and drag across a pair of chords in the player so it loops just that one change. When that's comfortable, play the whole loop: home, down, home, up. And when it's comfortable in one position, start in a different position and do it again. Then add the color notes and notice that your fingering never changes, but the roots and the chord-tone targets move in a way that makes your playing more musical.

Exercise 7-14: Put on the Andalusian cadence track below. Loop each pair of chords and practice the shift that goes with it, and then put them together and play over the whole cadence.

This is challenging, so take it slow. The goal here isn't speed. It's knowing where you're going before the chord gets there, and being able to stick the landing on every chord change. As always, treat these as starting points and make up your own variations.

So that's the sixth operation. We had skip, stack, edit, rotate, repeat, and now switch. Gear shifts are a deep, advanced topic, and I've only opened the door here, but the two shifts you saw in this section cover a lot of music.