The human brain can only keep a handful of things in mind at once. This fundamental bottleneck in our working memory applies to every domain. However, even though we can only keep a few things actively in mind, the loophole is that, with practice, we can build up arbitrarily rich “chunks” that each take up only one “slot” in our working memory.
These chunks allow experienced players to operate intuitively using what psychologist Daniel Kahneman calls System 1 thinking—fast, pattern-based, and automatic—instead of the slower, deliberate System 2 mode that beginners rely on.
To build those rich chunks, we’ll use a strategy called limitation exercises. These exercises simplify the musical context (and the overall difficulty level of improvising) by restricting variables. For example, we might limit things to one chord (an E7 vamp), one scale (E minor pentatonic), and one small area of the fretboard using a single geometric pattern. This makes it easier to focus on the sound, feel, and musicality of the notes without overwhelming the brain’s limited processing capacity. The goal is to allow you to internalize fretboard knowledge and scale patterns through repetition in a controlled environment, gradually shifting your understanding from System 2 to System 1.
Whenever you feel overwhelmed by an exercise, that’s a signal to simplify things even more.
Some definitions that will be useful throughout the course:
If we start on any note on the E or A string and play a note that is two strings and two frets higher, that note is separated from the first note by exactly an octave.
This same shape works over most of the fretboard because most strings are separated by the equivalent of five frets. So, (2 strings) x (5 frets/string) = 10 frets, and then we add two more frets to make 12 for a full octave.
However, the G and B strings are only separated by four frets, and that difference warps the shape of any geometric pattern that crosses it. We can visualize this as an imaginary line that sits between the G and B strings:
Whenever a geometric pattern lies across that imaginary line, the part on the high B and E strings is shifted one fret toward the bridge (or, equivalently, the part on the lower strings is shifted one fret toward the nut), so our octave shape ends up looking like this, with a three-fret span:
The name warp comes from Jon Finn’s book Advanced Modern Rock Guitar Improvisation. He calls it the “warp refraction threshold,” but I shorten it to the warp.
Memorize this: The two-string, two-fret octave relationship is the most fundamental move on the fretboard:
Importantly, this octave move works just as well in reverse, to go down an octave.
Memorize this: Apart from the octave, the most fundamental shape to master is one I call the stack:
The stack shape sits on three adjacent strings, each with two notes separated by two frets. Depending on which strings it sits on, it can look “normal” or appear in one of two different warped shapes:
The stack is the most powerful way to learn to play the pentatonic scale. There are five notes in the scale—four of them occur once in the pattern, and one occurs twice (the lowest and highest notes are an octave apart). When this shape represents the minor pentatonic scale, the root is the higher note on the middle string.
Memorize this: The minor pentatonic scale has its root on the upper note of the middle string:
In this module, one important goal is to memorize the positions of all the E notes on the fretboard. This will enable you to play the E minor pentatonic scale across the entire fretboard without memorizing scale patterns. Here are all the E notes on a 22-fret guitar:
You can find all of these locations (except for the open high E string) by starting from another E note and using the octave shape you learned in 1-3.
Exercise 1: Practice using octave shapes to find E notes. Start at the open or 12th fret of the low E string or the 7th or 19th fret of the A string.
Exercise 2: Practice using octave shapes to find E notes in reverse. Start at the 12th fret of the high E string or the 5th or 17th fret of the B string.
Exercise 3: Practice finding the E notes one string at a time. There are two Es on every string, one 12 frets higher than the other.
Exercise 4: Try choosing a random fret and find the nearest E notes toward the bridge and toward the nut.
Exercise 5: Try placing your hand in playing position at a random spot on the fretboard and identify all of the E notes that are under your fingers.
We’ll make these exercises a bit more interesting in the next section.
The goal of these exercises is build speed at finding E notes on the fretboard and to get practice playing the minor pentatonic scale in different locations using the minor pentatonic stack shape.
Each exercise will combine a lick (a sequence of notes played within the stack) and a note-finding strategy. I highly encourage you to mix and match licks and note-finding strategies to create your own exercises.
The basic idea is:
Here are some sample phrase ideas:
Here are some root-finding strategies:
Exercise 1-16: If you mix and match the phrase ideas with the note-finding strategies, there are 16 exercises here, and you can extend that even further by inventing your own licks and note-finding strategies.
The hardest part of these exercises is watching out for how the stack falls across the warp. It pays to focus your attention on that!
The first improvisation exercise is to use the minor pentatonic stack shape to play over a dominant seventh vamp. Don’t worry if you don’t know exactly what that means yet. The details will come later.
There are four notes in an E7 chord: E (root), G# (third), B (fifth), and D (flat seventh). It’s worth memorizing where the four notes of a dominant seventh chord fall relative to the minor pentatonic stack. Note that these notes always fall in the same locations in the stack, so you can use them across the entire fretboard.
The root, fifth, and flat 7th are all part of the pentatonic scale, so they all sound consonant, meaning they fit well with the chord. The root (the red circle) and the fifth (the blue square) fit exceptionally well, so they are great places to end a phrase when you want it to feel like you’re making a statement. Ending a phrase on one of the other notes can sound more like a question.
The other notes in the stack (the ones in black) are best used as passing notes. If you emphasize them too much, they may clash with the backing track.
It is worth noting that you can bend the upper note on the upper string up a whole step (the equivalent of two frets) to reach another fifth one octave above the one in the stack. This bend sounds great and is widely used.
It’s also very common to give the lower note on the upper string a small bend into the grey area between its normal pitch and the note one fret higher. When you play this bend, make sure you choke off or mute the note before releasing your bend. Ideally, you will hear the pitch rise but not fall.
Memorize this: In this diagram, the red and blue notes are great target notes when playing a minor pentatonic scale over a dominant seventh chord. Just remember to give the lower note on the upper string a slight bend up.
Exercise 1: In one stack position, over the E7 vamp backing track, practice creating phrases that end on the root.
Exercise 2: In one stack position, over the E7 vamp, practice creating phrases that end on the minor third (the lower note on the upper string). Practice giving this note a slight bend when you land on it, or hammer-on to the note one fret higher.
Exercise 3: In one stack position, over the E7 vamp, practice creating different phrases that target each of the chord tones.
Practice these exercises in different stack locations, ensuring that you get used to playing phrases and targeting notes when the stack lies across the warp.
E7 Vamp
E minor · 88 BPM · one-chord vamp
The Module 1 backing track, with the E minor pentatonic stack drawn on the fretboard and the E7 chord tones marked on it. Four bars of E7 and nothing else, which is the point of a vamp: one chord means every bit of your attention can go to where a phrase starts and where it lands. Slow the tempo down if you want more room to think between phrases.