Rule of the Octave – Major

Ascending

Sol
Mi
Do		 Ti
Sol
Fa
Re		 Do
Sol
Mi		 Re
Do
La
Fa		 Re
Ti
Sol		 Fa
Do
La		 Sol
Fa
Re
Ti		 Sol
Mi
Do
I V43 I6 ii65 V IV6 V65 I
1 2 3 4 5 6 7 8

Descending

Sol
Mi
Do		 Sol
Re
Ti		 Fi
Re
Do
La		 Sol
Re
Ti
Sol		 Re
Ti
Sol
Fa		 Do
Sol
Mi		 Ti
Sol
Fa
Re		 Sol
Mi
Do
I V6 V43/V V V42 I6 V43 I
8 7 6 5 4 3 2 1
  • Stable Scale Degrees = 5/3 voicing
  • Unstable Scale Degrees = 6/3 (sometimes with an added seventh)
  • Maximum instability – in the form of inverted 7th chords – occurs before resolution to a stable 5/3 sonority.
  • The third scale degree is partially stable – a tonic triad in 1st inversion. It is approached by a 4/3 dissonance from below and a 4/2 dissonance from above.

See also: Chord Grid (major)