Scales and modes

Modes are in fashion in jazz instruction - "a la mode", as they say in France. They're described in dozens of books and web resources, so I don't need to go into it all here. I'll concentrate on just the two issues, what is a mode and where should a beginner start with this material.


What are modes?

A mode (as the term is used in jazz) is the scale you get by starting somewhere in the middle of a familiar scale. For example, take the C major scale and play the notes from G to G. You'll get G-A-B-C-D-E-F-G, which is not the G major scale - that would have an F#. This scale is referred to as the 5th mode of the C major scale (because we started on G, the 5th note in C major). They also call it the G mixolydian scale or G mixolydian mode, which is a name derived from medieval church music.

Some teachers intentionally avoid the word mode and greek names like mixolydian, since they consider this complicates things unnecessarily. Instead, they refer to these derived scales as chord scales, and they'd refer to my example above as the G7 scale, since it fits that chord very well.

What modes are used for is as a basis for improvising. G mixolydian is a safe, vanilla choice for improvising over G7. Note that this is the same thing as the exercise in the section on ii-V-I's, where you're improvising over a G7 using a C major fingering while keeping in mind that G, B, D and F are your chord tones here. You can see G mixolydian as just a fancy name for this exercise. Modes are also used over chords that they don't fit quite so obviously, to achieve cool modern sounds - but that's more advanced than I want to get into here.

You'll also hear the term "modal jazz" being used. This is a style of jazz composition consciously based on modes. The classic example is Miles Davis' So What, which is 8 measures of D dorian, 4 measures of Eb dorian and 4 more of D dorian.

Some beginners raise the objection, G mixolydian is by definition the same set of notes as C major, so what's the point - why not just play C major? This misunderstands what a scale is. It's not just a collection of notes, the sequence is important too. F is the 4th of C major, but the 7th of G mixolydian. Whether a note is the 4th or the 7th of a scale tells you a lot about what to do with it when improvising.

A more valid objection is, it's easier to play a G7 scale by flattening the 7th of a G major fingering than by figuring out which scale it's the 5th mode of. To me, this is just a question of taste - I personally find it easier to use the same major scale fingering all the time than to remember which tones I have to flatten/sharpen, but if you prefer the other way then that's valid too.


Where to start?

Since you can start on any of 7 different notes of the major scale, there are 7 modes of the major scale. Similarly 7 modes of the melodic and harmonic minor scales, most of them also with the exotic greek names. So it's quite a lot to learn. Where to start?

In my opinion it's worthwhile working with the 2nd, 5th and 1st modes of the major scale from early on - in C major, that's D dorian, G mixolydian and C ionian (the last is just a synonym for the major scale). Those three are fine for beginners - the other 4 major scale modes and the modes of the minor scales can wait.

You can use dorian, mixolydian, ionian for improvising over a ii-V-I in C out of a C major fingering. I find I need to play the arpeggios of the three chords out of the same fingering first, to fix in my mind where the chord tones are for each chord - that helps to make sure you really are playing the 3 different modes, and not just C major throughout.

Learn to do this within a major scale fingering with the root on the 6th string and one with the root on the 5th string. That way you'll be able to solo over ii-V-I's in any key by shifting the pattern around between the 3rd and 9th frets.