Understanding Diminished Chords and Dissonance

Dissonance is a concept in music that refers to how well two specific notes go together. Consonant notes blend together with little problems, so they are very common in music. Dissonant notes do not blend well together and make it very obvious that two different notes are playing at the same time.

Usually the dissonant sound is unpleasant, but dissonant notes are very effective at creating tension. The diminished chord is a slight alteration to the minor chord. Understanding diminished chords and dissonance can open up a variety of range to a musician’s repertoire.

Each note in music has a varying level of dissonance compared to the root note. As odd as it may seem, the most dissonant notes are the notes found close to the most consonant notes. The most consonant notes, which blend together the most smoothly are the unison, octave and perfect fifth notes.

The most dissonant notes are the second, seventh and diminished fifth notes, which are located next to the perfect consonances. The reason these notes are so dissonant is actually because they are so close to the consonant notes. The nearness of the frequency of these notes heightens the stress the note causes when placed over the root.

The minor chord consists of the 1, b3, 5 notes. The 1 and 5 notes are perfect consonances and the b3 is still a fairly consonant note. The chord blends very well together as a result of the overall consonance of the notes.

The diminished chord consists of the 1, b3, b5 notes. Instead of having the perfectly consonant 5 note, the diminished chord replaced it with the b5, the most dissonant of all the notes. The introduction of the b5, while seemingly a minor change causes the diminished chord to sound much tenser than the minor chord it is largely based off of.

One important aspect of understanding diminished chords and dissonance knowing when they should be used. The diminished chord and the dissonant b5 note rarely get emphasized or appear in songs. When they are used, it is to help create more tension to the song, which would not occur using more consonant chords and notes.

For example, “Space Oddity” by David Bowie and “Don’t Look Back In Anger” by Oasis use the diminished chord structure. These songs are tenser as a result of what would seem like a minor change compared to just using the more conventional minor chord on piano. However, neither David Bowie nor Oasis heavily uses the diminished chord or dissonance in their other songs. It is appropriate for some songs and not others.

The diminished chord and dissonant notes can open up possibilities that are not possible when trying to write a song with more conventional constructs, like the major or minor chords. Dissonance subverts the expectations of the listener, drawing attention to the note in the process.

However, the key to understanding and using diminished chords and dissonance is discretion. You should only use dissonant notes and diminished chords when you want to create a sense of tension, but it should not be something you attempt to use all of the time. Very few musicians write enough songs of that nature to base their entire composing style around dissonance.