Most Western music has 12 notes and 12 keys. The chromatic scale consists of all 12 notes. Of course other types of music may have notes in between. Blues music for instance takes advantage of note-bending and sliding between notes as well as the infamous ♯4/♭5—which we will learn later.
Most of us are familiar with the Diatonic scale, which consists of 7 notes. A diatonic scale is any heptatonic scale that includes five whole steps and two half steps in each octave.
For instance, C major is a diatonic scale with no flats or sharps.
If you remove one of the notes from the diatonic scale, it becomes a hexatonic scale. To start, though, let's focus on the diatonic scale.
A Whole Note is two frets on a guitar string and a Half note is one fret on a guitar string.
For the examples below, W = Whole and H = Half.
This goes from the Starting Point to the Octave with notes in between every W or H.
The Major scale (otherwise known as Ionian in music theory) is WWHWWWH.
Ionian = _ W _ W _ H _ W _ W _ W _ H
For the Key of C, C would be the starting point. If we use the formula we come up with C, D, E, F, G, A, B, C (Octave).
You can play the C major scale on the A string (5th string) of the guitar like this:
3 - 5 - 7 - 8 - 10 - 12 - 14 - 15 **The numbers represent where you place your finger on the fretboard**
The key of G is G, A, B, C, D, E, F♯, G. You can play the G major scale on the E string (6th and 1st string) of the guitar like this:
3 - 5 - 7 - 8 - 10 - 12 - 14 - 15 **The numbers represent where you place your finger on the fretboard**
♫ If you use the same formula but start in a different place, you come up with the relative modes. You can also use a mode for a different kind of sound (musical/stylistic).
Ionian = W W H W W W H
Dorian = W H W W W H W
Phrygian = H W W W H W W
Lydian = W W W H W W H
Mixolydian = W W H W W H W
Aeolian = W H W W H W W
Locrian = H W W H W W W
Keep in mind that the Ionian mode is the normal formula for the major scale and Aeolian mode is the same formula as the normal minor scale.
The Nashville Number System is an easy way for session musicians to transpose (change keys), because the chords are based on their relative pitch.
A capitalized Roman numeral is a Major chord and a lowercase Roman numeral is a minor chord.
I = 1 Major, ii = 2 minor, iii = 3 minor, IV = 4 Major, V = 5 Major, vi = 6 minor, viio = 7 diminished (minor and flat 5th)
That is the Ionian scale harmonized, by the way!
You could also have chords not in the scale, like a ♭VII which is a Flat 7 Major or a ♭III which is a Flat 3 Major.
Let’s apply what we learned to chords by harmonizing the scales/modes.
A · Bm · C♯m · D · E · F♯m · G♯o
Keep in mind that for the relative modes, you just start in a different place of the regular major scale. So using A major:
If you start on the 2nd chord (B minor), you get the Dorian mode.
If you start on the 3rd chord (C♯ minor), you get the Phrygian mode.
If you start on the 4th chord (D Major), you get the Lydian mode.
If you start on the 5th chord (E Major), you get the Mixolydian mode.
If you start on the 6th chord (F♯ minor), you get the Aeolian mode.
If you start on the 7th chord (G♯ diminished), you get the Locrian mode.
This is the key of: A, whose relative minor is F♯m.
| 1 (I) | 2 (II) | 3 (III) | 4 (IV) | 5 (V) | 6 (VI) | 7 (VII) | |
|---|---|---|---|---|---|---|---|
| Ionian | A | Bm | C♯m | D | E | F♯m | G♯o |
| Dorian | Am | Bm | C | D | Em | F♯mo | G |
| Phrygian | Am | B♭ | C | Dm | Eo | F | Gm |
| Lydian | A | B | C♯m | D♯o | E | F♯m | G♯m |
| Mixolydian | A | Bm | C♯o | D | Em | F♯m | G |
| Aeolian | Am | Bo | C | Dm | Em | F | G |
| Locrian | Ao | B♭ | Cm | Dm | E♭ | F | Gm |
If we keep going up in the Diatonic scale past the octave which is 8, we can figure out the extensions!
9 = 2
11 = 4
13 = 6
Keep in mind that this is a bit of an exaggeration because these notes are typically higher than the rest of the chord. These are usually used with 7th chords.
D Major is D, F♯, and A
D7 is D, F♯, A and C
C is the 7 (Dominant 7)
D9 is D, F♯, A, C, and E
E is the 9 which is the 2 above the octave.