Contextualised Composition and Theory

1
Contextualised Composition and Theory

• Keys, chords harmony
• Introduction

2
What we will cover

• The harmonic series
• The hierarchy of notes within a major scale
• The function of the dominant seventh chord

3
Keys

• What is the function of keys in tonal music?
• Provides centre, or tonic
• Gives colour and contrast, light and shade
• Adds drama with elements of tonal certainty and
  uncertainty
• Haydn Symphony No. 26
• Wagner Prelude to Tristan un Isolde
• Mahler Symphony No. 10

4
The harmonic series

• The harmonic series is the fundamental principle
  of musical pitch
• Everything that vibrates creates a series of
  overtones or harmonics

5
The harmonics

• Note how the intervals unfold octave, fifth,
  fourth, major third, minor third to reveal the
  shape of a major triad

The major triad major 3rd plus minor 3rd
6
The hierarchy of the scale

• Each of the seven notes of the major scale have
  an individual character and function in
  relationship to the key note or tonic
• The tonic is the strongest note
• The dominant
• and leading note return music back to the tonic

7
The hierarchy of the scale

• The third degree, or mediant, and its distance
  from the tonic defines the tonality of the key
  (major or minor)
• The second degree, or supertonic, has a close,
  downward leaning to the tonic and so has a strong
  character
• The fourth degree, or subdominant, has a strong
  leaning to the third
• The sixth degree, or submediant, has a leaning to
  the dominant but of a tone, not a semitone. This
  is a fairly weak degree

8
The hierarchy of the scale

• From this information it is possible to create a
  hierarchy of the seven pitches starting with the
  strongest, the tonic
• Of course this is highly subjective and it is
  important to note that keys, tonal systems and
  tonal hierarchies are cultural and not subject to
  any physical law

9
The hierarchy of the scale

• But if we return to the harmonic series is
  evident that the fourth and sixth degrees of the
  scale appear later than the stronger degrees
• The dominant is the first new pitch and occurs
  three times in the first three octaves of the
  series

10
The dominant and leading note

• Their function in Western Classical music is to
  return harmony back to the tonic
• The leading note, as it lies a semitone under the
  tonic, has a strong upwards lean

11
The dominant and leading note

• The a triad built on a dominant contains the
  leading note and supertonic, both of which have a
  powerful pull to the tonic

12
The dominant seventh

• Add a seventh to the chord (subdominant) and the
  note will have a very strong semitonal lean down
  to the third (mediant)

13
The dominant seventh

• The function of the dominant and dominant seventh
  chords is to return the harmony to the tonic
• How might a dominant or dominant seventh chord be
  used to modulate to a new key, for example from C
  major to G major?
• Use the dominant or dominant seventh chord of the
  new key