The Dominant Chord

• stacking another third on top of our diatonic chords will give us sets of chords of the seventh

• the most is important is that on the 5th scale degree
  • this chord is the chord of the dominant seventh or dominant chord for short
    • it has rules for resolution into the tonic chord
      • 7th of the dominant → down one scale degree [like all dissonance] to the 3rd of the tonic triad
      • 5th of the dominant → down/up one scale degree to the 3rd/fundamental of the tonic triad
        • more frequently the latter
      • 3rd of the dominant → up one scale degree [as leading tone] to the fundamental of the tonic triad
      • fundamental of the dominant → leaps up fourth/down a fifth to the fundamental of the tonic triad

• with this type of voice leading the 5th is omitted from the tonic
• often the dominant has the 5th omitted
  • rarely the third
• there are three inversions of the dominant chord

• I = chord of the sixth and fifth
• II = chord of the fourth and third
• III = chord of the second
  • the one exception to the voice leading of these chords lies in the fact that the fundamental [G in this case] must remain stationary to complete the tonic triad
• leading of the 5th of the dominant can be led upward if necessary
  • this will give rise to doubled third in the tonic

APPENDIX TO CHAPTER X

• special cases for voice leading
• dominant 7th lead to a chord of the sixth by the bass moving a m3 down
  • always move the leading tone up to the tonic
• dominant 7th lead to a chord of the six four means the bass stays in the same position
  • if there are two fundamentals then they must stay in the same voice
• the dominants 7th and 3rd can move oddly when they are in the inner voices
  • contrary motion must still apply as they will otherwise lead to P5 or P8
• if the 5th is in the Soprano or Tenor voice in a dominant third inversion chord then it may leap a fourth up or a fifth down
  • the faulty progression should be avoided
• don’t forget to double the fundamental of the dominant chord
  • when in inversions – one can sometimes omit the 5th and double the fundamental