Mode Chord Relationships

In this lesson we will look at how to use modes over chords, and how to combine modes for different harmonic ideas. Now the basic theory about playing modes and scales over chords is that the all the notes in the chord must be in the scale if you want to avoid clashing notes. Obviously this gives a huge scale choice over something like a minor chord.

Lets look at Cm. Cm is made up of the following intervals 1, b3, 5 and the notes are C, Eb, G. So any scale with those notes in can be played over the chord.

But, I hear you shout, Eb Major, Ab Major, Bb Major all contain these notes, and surely you cant play Ab Major over Cm?

Well, you can. Because Ab Major consists of Ab, Bb, C, Db, Eb, F, G. And by rearranging the scale and starting with the note C, we get C Phrygian! which is a minor mode! Bb gives us C Dorian, and Eb gives us C Aeolian.

So lets say we want to create a chord progression which allows us to stay in the key of Cm, or C Aeolian. That means we can use all of the chords which can be made up from the scale of Eb.

  • I-Eb, Ebmaj7, EbMaj9
  • II-Fm7, Fm9
  • III- Gm7
  • IV- Abmaj7, Abmaj9, AbMaj7#11
  • V- Bb7, Bb9, Bb11, Bb13.
  • VI- Cm7, Cm9, Cm11
  • VII- Ddim.

Now all these chords work with Cm. Why? Because Cm is the relative minor of Eb. That basically means Eb is C Minor, but this is where it gets interesting. If you play C minor over these chords, the notes may stay the same, but the sound will change. C minor will sound happy over Eb, Jazzy over Fm7, Dark over Gm7 etc.

Its because technically speaking the Cm morphs into Eb Ionian, F Dorian, G Phrygian etc! Same notes, different sound. And thats the secret of chords and modes you can play the same notes over different chords and get vastly different sounds.

This theory can be used with any mode just find what the parent scale is. By that I mean E Aeolian is the 6th mode of G major, and then using a book, or whatever, work out all the chords you can get from the modes of G major.

To find out what scales to use over chords, simply write out the notes of the chord, superimpose them onto the key's major scale, see what formula you get, and that will give you the scale or mode. Confused? Well, using Cm again, we have the notes

C, Eb, G and the C major scale has the notes C, D, E, F, G, A, B.

Which means the chord contains the formula 1 b3 5. Now any C mode with this formula can be used over the chord.

That's it hope you enjoy!