Previously in the music theory series we discussed diatonic chords built off the major scale and those chords are considered either major or minor. I mentioned that we’d come back to the vii chord later. Well the vii chord is actually built off the seventh degree of the scale and is considered a diminished chord. So what is a diminished chord? Let’s take a look at diatonic chords of a C Major scale on the treble clef…
Go ahead a play these on your piano or keyboard so you can hear how each of these chords sound to your ear.
As you can see/hear, the Major Chords are I IV V. In this case C Major, F Major, G Major. Also known as a I IV V progression.
Minor Chords are ii iii vi. d minor, e minor, a minor. Also known as a ii iii vi progression.
The diminished chord is vii. In this case b diminished chord. To our ears, major and minor sounds more consonant meaning it sounds good together or pleasing to the ear. However diminished chords sound more dissonant and needing a more pleasant resolve like the I chord. A good way to think of this is a minor triad has a flat third degree compared to a major chord, so the formula for any minor triad is 1 – flat 3 – 5 (C -E flat – G). Diminished chords have a flat fifth degree compared to a minor chord, so the formula for a diminished triad is always 1 – flat 3 – flat 5. So a minor triad with a flat 5th. If you were to build one off the note C, it would be C, E flat, G flat.
Until next time try playing these triads in different major keys and noticing how each chord sounds and how every time the vii chord or diminished chord wants to resolve to the I chord. You can also practice building diminished triads off any note.