Relative Scales

My approach to scale memorization entirely revolves around relativity. Understanding how everything relates to the major scale can drastically reduce the amount of memorization needed to play different scales across the fretboard.

I consider scales as falling into one of two categories. Either re-framings of the major scale, or alterations to the major scale.

Re-framing the major scale

You’ll often see each mode described as an alteration to the major scale rather than a re-framing, but I believe this to be an over-complication.

The diagram above shows the interval sequence for each mode. As you can see they are essentially identical, with the only difference being where the sequence begins for each mode. If you start a major scale from its second note, and play to the octave of that second note, you will have just played the second mode of the major scale.

The root of this modal scale will be different to the root of the major scale you started with. If you apply this concept to the scale C major, you will end up playing D dorian. Start from the third note rather than the second and you’ll play E phrygian.

All of the scales you can play starting from each note of the major scale will contain the exact same notes, just in different orders. This means that if we were to create a map of these scales across the entire fretboard of the guitar, they would look identical.

Application

With this relativity in mind, we can reuse shapes across the fretboard to play in whichever mode we please. This is assuming you have memorized the major scale in all of its positions, which can be done with as little as three shapes.

All we need to do is figure out the root note of the major scale which is relative to the modal scale we wish to play. Memorizing the modes in the order listed above is vital. The mnemonic "I don't particularly like modes a lot" is helpful, with the joint function of reminding you that “a lot” is, in fact, two words. Note that the “ionian” mode is the major scale.

Open YouTube and search for an A dorian backing track in whatever style you want. Dorian is the second mode of the major scale, so we need to find the root of the major scale with A as its second note. This exercise has the benefit of also helping you to learn the shape of particular intervals on the fretboard. The scale we are looking for is G major.

Our tonic note is still A, but we can position shapes as if we were playing in G major. Try playing the G major scale from its second note the the octave of the second note. That’s A dorian.

The Minor Pentatonic Scale

Take another look at the diagram above. The sixth mode is “aeolian”, otherwise known as natural minor. The relationship between the major scale and its modes directly concerns the minor scale as a result. You may already be aware of the term “relative minor”.

The minor pentatonic scale is a minor scale with two notes removed. “Penta” (five) “tonic” (notes). Anywhere you can play a minor scale is a place you can play a minor pentatonic scale. As a result of scale relativity, the minor pentatonic scale can be employed when improvising in any mode.

Lets take A dorian as an example one more time. If I would like to use minor pentatonic shapes to improvise, I need to find the root of the minor scale that is relative to A dorian. We figured that G was the root of the relative major of A dorian, and from here we now need to find the root of the relative aeolian. As aeolian is the sixth mode, we just need to figure out what the sixth note in G major is. That note is E.

Try playing E minor pentatonic over the same A dorian backing track you used before. It should sound totally fine.

Playing over modal backing tracks can be fun, but I personally find it more interesting to apply modes in other contexts.

Each mode is generally considered to have either a major or minor quality. As a result, they can be used to improvise in their parallel major or minor keys. Their qualities correspond to the quality of their I chord (read my post on functional harmony for more details).

The diatonic ii chord is minor in quality, and the second mode is considered to be minor also. The IV chord is major in quality, as is the fourth mode.

Let’s take that fourth mode for example. If you have a backing track in F major, you may want to try playing F lydian over it. To do this using our methodology, we would have to find the root of the major scale which has F as its fourth note. The answer in this case is C. Load up an F major backing track and give it a go. Position all of your shapes as you would for C major, and attempt to treat F as your root.

For a C minor backing track, you may want to try playing C dorian. Dorian is the second mode, so we need to find the root of the scale with C as its second note. In this case, it is B♭.

Altering the Major Scale

Modes of the Harmonic Minor Scale

The harmonic minor scale is described as a minor scale with a raised seventh degree. This is an explicit modification to the scale.

This scale can also be described as the sixth mode of ionian #5. Ionian, as mentioned above, is the major scale, and #5 describes an explicit modification to that scale.

Try playing C major in two octaves, but sharpen the fifth degree by a semitone each time you play it. Now, try the same exercise starting at the sixth note of the scale. That’s A harmonic minor.

In order to play all of the modes of the harmonic minor scale, you simply need to learn how to sharpen the fifth degree in all of your major scale shapes. Apply the same re-framing process described above and voilà. You can now play:

Harmonic minor
Locrian natural 6
Ionian #5
Dorian #11
Phrygian dominant
Lydian #2
Super-locrian

Extending to Other scales

There are other groups of scales that can be memorized using the same principals as above. Here are some you can research:

Ascending melodic minor (sixth mode of the lydian augmented scale)
Double harmonic major
Harmonic major
Neopolitan major and minor

Each of these scales are explicit alterations to the shapes you will have memorized, and each have seven modes. While theses scales themselves might not be particularly well known, some of their modes definitely are. For example, the fourth mode of the double harmonic major scale is Hungarian minor. This scale features prominently in the music of Django Reinhardt and is a staple of Gypsy jazz, and is even alternatively known as the Gypsy minor scale.