A brief and quick explanation on how to harmonize a major scale, how the chords on each note is created and how all the modes emerge out of this.


Western Music Theory: Ionian

This is the first mode, Ionian. It is the base we just need to take as given for now. This scale often is also called the “natural major scale”, though this might already provoke some paradigm discussions, as a truly “nature given” base for music might be the overtone series only. But this is a topic for itself, sooner or later we will deal with this in depth also!

For now, let’s just take this scale as the base. Practically, this one is very well know, you can simply play it on your instrument and surely you will feel kind of familiar with it.

Let’s have a look at the structure, and especially at the intervals towards the first note, the root note (r):
We can simply give each note a number, which already shows the intervals. Numbers with no “b” or nor “#” are all the natural or the big intervals. So a “3” is a major third, and a “b3” would be a minor third.

So this first scale is called “Ionian”, and it has the intervals:

r – 2 – 3 – 4 – 5 – 6 – 7 – r

and in the key of c this are the notes: c – d – e – f – g – a – b – c

I use the “r” for the root note. When we jump every 2nd note and stack them we get a chord, or when we play them one after another, we get an arpeggio. So the 7th chord in the key of c is a Cmaj7. “7th chord” means that we stack only 4 notes, up to the 7, therefore “7th chord”. But we can go on all the way through, and in the upper octave we get the so-called “options”:

9 – 11 – 13

The 9 is the octave of the 2, the 11 the octave of the 4 and the 13 the octave of the 6. Written as chord this would be a “Cmaj7 9 11 13”.


Harmonizing the scale

Harmonizing a scale means, that we keep the same absolute notes, so in this example the notes of the “C Major Scale”, which are: c d e f g a b c, but we re-define the root note. And because this scale is not symmetrically, the structure and the intervals towards this new root note will change! This is how we create all the other modes (Ionian – Dorian – Phrygian – Lydian – Mixolydian – Aeolian – Locrian), and also all the other chord types (Cmaj7 – Dm7 – Em7 – Fmaj7 – G7 – Am7 – Bb7b5).

The chords

maj7   “Major Seven”  r  3  5  7
-7 or m7   “Minor Seven”    r  b3  5  b7
7 or dom7   “Dominant Seven”    r  3  5  b7
-7b5 or m7b5   “Minor Seven flat Five”    1  b3  b5  b7


By harmonizing the major scale (Ionian) we get all those different scales and different chords, but we do stay in the same key. Meaning we will use always the same notes, just switching the point of reference. So all we do is to re-define the root note. In this example, it is the key of Cmaj, and we will only use the notes c d e f g a b c:


Western Music Theory: Dorian

This is the second mode, the Dorian scale. Characteristics are:

  • minor 3 (b3)
  • natural 6

The 6 is characteristic, because the two other minor scales which emerge out of this system (Aeolian and Phrygian), both have a b6, and the 6 reminds a bit of a major scale, giving a little bright color.


Western Music Theory: Phrygian

Third mode Phrygian, characteristics are:

  • flat 2 (b2) – very particular and strong sound, as in western context a little exotic
  • minor 3 (b3)
  • flat 6 (b6)

The Phrygian scale has a very unique character with a little “oriental touch”. Later we will explore some other scales like the “Phrygian Major” and others, coming from other scale systems (Melodic and Harmonic Minor) which we can relate to this sound. It is good to start exploring the Phrygian scale, e.g. with a drone, to get know to this particular sound, although it might be a not very prominent or common sound in most western music.


Western Music Theory: Lydian

Forth mode, Lydian, a very bright sound. Most prominent:

  • sharp 4 (#4)
  • major 7 & major 3

This is a tritone, a quite particular interval with a very strange history in the western music history. It was considered “the devil in the music”, but when exploring this color in the context of the Lydian sound, and maybe also in the Hindustani context looking at Raag Yaman, we might get the impression that there was a conspiracy at work 😉 Actually, in this context the #4 (or #11) feels very bright with a lot of light in it.

The tritone within the Dominant 7 chord on the “V” happens in a very different context (see below when discussing Mixolydian).


Western Music Theory: Mixolydian

The 5th mode, especially the function of the chord, is very important in the practical live of western music. First let’s look at the characteristic notes of the mode:

  • major 3
  • flat 7 (b7)

Usually flat 7 happen only in the minor scales, this one is the only major scale within this system, where we have a major 3 together with a flat 7. And the interval between the 3 and the b7 happens to be the tritone. It is the same interval like the root to the #4 in the Lydian mode. In the key of C Major this are the notes b and f that we are talking about.

In the context of the Mixolydian Scale and the Dominant 7 Chord this tritone creates a special tension which wants to get resolved, and this is why we have the typical V-I movement in chord progressions so often (G7 – Cmaj7).


Western Music Theory: Aeolian

The sixth mode, Aeolian. Also called “natural minor”, or the “parallel minor” (to the first mode). Characteristics:

  • minor 3, flat 7
  • flat 6

The only difference to the Phyrgian mode is the natural 2, which is much more normal to our ear than the b2. Maybe this is a valid reason to call it “natural minor” … Anyway, for clarity I will always use the name “Aeolian”.


Western Music Theory: Locrian

The seventh mode, Locrian. Characteristics:

  • flat 5 (b5)
  • flat 2 (b2)
  • flat 6 (b6)

This scale has a even stronger character as the 3rd mode Phyrgian, and the seventh chord is the only “-7b5” (say: minor seven b five) in this system. The chord also is called “half-diminished”, because the interval structure is minor 3 (from root to b3), another minor 3 (from b3 to b5) but then a major 3 (from b5 to b7). There is also a full-diminished, but not in this system. The full-diminished is build of ONLY minor 3rds, so to the root a full diminished would have: r – b3 – b5 – 6 (or bb7). Just as a side note to explain the name, later more on this!

Sometimes Locrian and the -7b5 chord is also related to kind of a dominant function, as this is also a sound that demands to be resolved to the I.




Basic Western Theory: The Ionian System