The modal scales are built from the major scale and contain the same notes as this parent scale. Each mode starts on a different note in the parent scale. It is very important to remember that the modal scales built from any particular major scale will contain the same notes as its parent. In the table below the Major scale, also known as the Ionian, is at the top and shows the usual Major scale interval pattern of: Tone, Tone, Semitone (between 3rd and 4th), Tone, Tone, Tone, Semitone (between 7th and 1st). [TTSTTTS]
Then each of the modes start on the following notes in the Major scale on the left (the numbers are the note of the parent Major scale). The coloured notes are the notes that are displaced relative to the Major scale pattern [TTSTTTS]. These are the notes that give the particular mode its character. They are sometimes called the character notes. Knowing these and how to use them is one of the most important aspect of using modes.
|the character notes for each mode|
|Mode||In Key||In Parent|
|Dorian||3b 7b||4 1|
|Phrygian||2b 3b 5# 7b||4 5 1 2|
|Aeolian||3b 5# 7b||1 4 5|
|Locrian||2b 3b 5b 5# 7b||1 2 4 5 6|
Modal Scale PatternsThe following are the seven modal scale patterns. The illustration is based on C Major. The red notes are the character notes of the mode. Notice that there are only five distinct positions. This is because the Ionian and Locrian are the same, bar one note. And the same is true of the Phrygian and the Lydian.
However, bear in mind that each pattern is only named after a mode because the root for that mode is on the 6th string. It is a very confusing convention. It would be better if, like with penatonic scales, we talked in terms of the 1st, 2nd, etc positions (imho!). In reality, any of the modal scales can be played in any of the five positions. You just need to be aware of where the root and the character notes are for a given mode in that position. When playing in a mode these notes need to be emphasised to reveal the modal sound.
So are the modal scale patterns useful? Well yes, because together they cover the whole fret board in a given Major key. The trick is to know the relative Major of the key you want to play in! So an easy example would be; you want to play in A minor, so you can play any modal pattern of C Major. Then to get the 'minor' sound you need to emphasis the 1st 4th and 5th of the relative Major scale. This is equivalent to playing A minor.
A more complicated example would be you want to play get a Phrygian sound over an Emin7 chord. Then you will need to play E Phrygian whose relative Major is again C. So you can play any modal pattern in C and emphasis the character notes the 1st and 4th. You will notice that the character notes are very similar to the previous example. The difference is they are being played against an Emin7 and it is this that gives the modal tonality... but you need to pick out the character notes for it to work effectively.
The position of the character notes within the scale patterns is more easily seen if we label the notes using the parent major scale's note number. If you know where the root note is then it is easy to find the character notes. The diagram below highlights the 1st 4th and 7th as these are the most common character notes. But, of course, the Aeolian mode has the 5th and the Locrian also has the 2nd and 6th. Notice that the 3rd is never a character note. This then can be considered to be the character note of the Ionian, the parent scale.
If you build a chord consisting of the root, 3rd and 5th from each of the modal scales you get 7 chords (usually labelled I II II IV V VI VII) some are major and some are minor because the 3rd is a flattened 3rd relative to the Major scale. So we have:
One of the many things to notice is how the the common blues progression I IV V is all the major triads.