The Triads of the Major Scale

• when constructing chords from the major scale, degrees 1,4,5 form major chords
  • these are the most primary chords of the major scale
  • tonic triad – the chord formed on scale degree 1
  • subdominant triad – the chord formed on scale degree 4
  • dominant triad – the chord formed on scale degree 5
  • the pitches of the tonic, subdominant, and dominant triads contain all the tones of the major scale
  • these three chords clearly outline the key, when used in conjunction
  • these three chords can be used to harmonize any diatonic melody
  • these three chords also outline the relationship of the Circle of Fifths
    • they are related by means of successive keys by their common tetrachords
• degrees 2,3,6 form minor chords when constructed from the major scale
  • they lack the same power, brilliance, and emphasis that the major chords have, but they serve to enlighten the major chords
  • they have the same relations in the Circle of Fifths [but now in terms of minor]
  • we can say that their relation to the major triads is the same as a parallel key
    • degrees 1+6, 3+5, 2+4 form minor thirds with one another
• the triads can be grouped into three families that denote function
  • tonic group – chords on the 1+6 degrees
  • dominant group – chords on the 3+5 degrees
  • subdominant group – chords on the 2+4 degrees
  • the chord that comes from the 7 degree is especially dissonant in nature and Tchaikovsky would rather us not deal with it until we master the connections of these first six primary chords