Consonance and Dissonance

The discovery of the mathematical proportions behind different sounds gave rise to the Greek theory of music, and to notions of consonance (stable, pleasing sounds) and dissonance (unstable, unpleasant sounds).

  • The Greeks believed that our ears innately wish any dissonance to be resolved (moved to a consonance).

  • In the Renaissance (1450-1600) these theories of consonance and dissonance informed all composing.

  • Composers learned strict rules about the relationships between notes, and these rules were rooted in Greek theory.

  • Dissonances were allowed; they provide tension and excitement in music. But because of their inherent instability, they needed to resolve quickly to a consonance.

The consonant intervals are the Unison, 3rd, 5th, 6th and the Octave:

The dissonant intervals are the 2nd, the 4th, the Augmented 4th (this is a 4th plus an additional semitone, and was so dissonant it was called the ‘Diabolus in Musica’, the ‘devil in music’ and was avoided at all costs!) and the 7th:

We find consonance, dissonance and resolution (moving from a dissonance to a consonance) in almost every piece of music today. This is one of the main reasons music sounds interesting. Of course, there is nothing modern listeners would find shocking or challenging about a dissonance, but it is an important part of understanding why certain songs affect us in a certain way.

Dissonance Activity

As a class, look at dissonance and resolution at work in Adele’s Someone Like You:

Someone Like You, by Adele/Daniel Wilson, UK (2010).

The song starts at 0’30’’; the passage you will focus on is from 0’45’’ to 1’06’’.

Look at the score and circle or highlight the following:

● The opening two notes in the vocal line (E and C sharp) are repeated a number of times at the beginning of the song (with the words ‘I heard’, ‘settled down’, ‘found a girl’, ‘married now’, ‘I heard’, etc.).

● 1st bar: the first E and C sharp form consonant intervals (5th and 3rd) with the A in the bass.

● 2nd bar: the E is consonant (6th) and the C sharp dissonant (4th) with the G sharp in the bass – this adds some tension and makes us feel the music needs to resolve.

● 3rd bar: the E is now dissonant (7th) and the C sharp consonant (5th) with the F sharp in the bass – there is still some tension.

● 4th bar: the E is dissonant (2nd) and the C sharp also dissonant (7th) with the D in the bass – there is now a great deal of tension in the music (to match the pained words ‘married now’). There is now huge musical tension that needs to resolve.

● 5th bar: phew! Back to A in the bass, which makes both the E (5th) and the C sharp (3rd) consonant again.

Activity 2. Consonant and dissonant intervals.

Consonant intervals: C= (1, 3, 5, 6, 8) Dissonant intervals: D=(2, 4, 7)

Using Seesaw or NoteFlight or ruled music manuscript paper: Create a blank Music Staff and copy these into a presentation. Count and label the intervals.

Piano Playing Exercise

Practise playing consonant intervals (Unison, 3rd, 5th, 6th, Octave) on a keyboard.

Questions

  1. How do these intervals sound? I.e. What is the effect of each note upon the other?

  1. Are there any intervals that sound better (more consonant) to your ear than others?

Practise playing the dissonant intervals (2nd, 4th, Augmented 4th, 7th), and consider:

  1. How do these intervals sound? I.e. What is the effect of each note upon the other?

  1. Are there any that sound particularly awful? I.e. When put together, which notes affect each other in ways that do not sound right to our ears?

Practise resolving the dissonant intervals to a neighbouring consonant interval (e.g. resolve a 2nd to a Unison or a 3rd; resolve a 7th to an Octave).

  1. How are the ‘resolved’ notes affected by each other?

  1. How do these resolutions sound?