Over the next few months we’ll be exploring the theory and usage of the most common scales guitarists use. Specifically we’ll be exploring the seven modes, which include the simple major and minor scales, and we’ll also be looking at the major and minor pentatonic scales as well as the blues scale. After we’ve covered the ‘basics’ we’ll look at the harmonic minor and the melodic minor scales, which are the most common variations on the natural minor scale; and finally look at a few modes of those minor scales. Hopefully, this series will end up as the most thorough and detailed explanation of scales for guitarists anywhere on the web! :fingers crossed:
Today though, we’ll start simple, and find out just what a scale is 🙂 .
So What’s a Scale?
Scales are simply a collection of (usually at least five) notes, with one of those notes being specified as the root. Any collection of notes with a root could be called a scale, so the number of theoretically possible scales is infinite. In reality though, history and common practice has distilled these infinite possibilities down to just a few basic scales, which form the basis of all other common scales.
So What is a Root?
The root note is a note which controls what kind of feeling or emotion a scale will imply. It is the most fundamental note of a scale, chord, or key, and it is the note against which every other note is judged/heard. We perceive every note of a scale, chord, or key as it relates to the root note.
Also the root note is the letter used to name scales, chords and keys. For instance a C major scale will have a ‘C’ as its root note; a Gmin chord will have a ‘G’ as its root; and a piece written in the key of ‘B’ will have a ‘B’ as the root.
The root note is the most important note in a scale, chord or key and so it is the note which receives the most ’emphasis’. Notes which are emphasised (especially harmonically) stand out to the ear, so we perceive this note as having a special importance in the scale, chord, or piece. In this sense the root is usually referred to as a key centre.
How Can the Root be Emphasised?
Scales are usually rehearsed starting and finishing on the root note – this naturally reinforces the importance of the root. Similarly, songs usually use chord progressions and a harmonic rhythm which emphasise a particular chord and note, and will typically begin or end on the root chord.
Harmonic context (the chords/chord progression) is usually the number one indicator in determining the key centre/root of a piece, and for determining which scales/modes are appropriate for melodic composition or improvisation.
What Are the Modes?
Let’s take the notes C, D, E, F, G, A, and B. If the note ‘C’ is taken as the root then these notes form the C major scale (we’ll talk about this more later); but if we take ‘A’ as the root then these notes form the A minor scale. The same set of notes can create two completely different scales depending on which note is the root.
These same notes (C, D, E, F, G, A, B) can also be known as D Dorian, E Phrygian, F Lydian, G Mixolydian, or B Locrian, depending on which note is taken as the root.
If scales are collections of notes, then modes are scales but with different notes taken as the root.
So How Do I Know Which Note is the Root?
Context! You need to listen to the underlying chord progression, rhythmic structure and melodic structure to determine which note is sounding like the key centre (i.e. which note is being ’emphasised’).
Here are a few mp3s for you to listen to. All of these mp3s use the same set of scale notes but every example has a different emotive quality and ‘flavour’ because of them each taking a different note as its root. To create context and hopefully make the differences between each mode more obvious, I have phrased the mode to emphasis the root notes and I have included a chordal backing to create harmonic context.
Hopefully this article hasn’t scared you off modes and scales – I promise everything will become clear in the coming articles. All that you should have taken from this post is that scales are collections of notes. Modes are scales but with different notes taken as the root. And the easiest way to tell one mode from another is to listen critically and decide for yourself which note sounds like a key centre.