Rules for 6ths:
- The intervals that are white notes use only white piano keys. Those that are black notes use at least one black piano key.
- 6ths use six letters. (For example, C—A is C D E F G A.) Their “size” depends on how many keys we skip.
- A diminished 6th skips six keys. It is three whole steps + a half step.
- A minor 6th skips seven keys. It is four whole steps.
- A Major 6th skips eight keys. It is four whole steps + a half step.
- An augmented 6th skips nine keys. It is five whole steps.
Note to more advanced students:
- Circle one shows an unusual spelling of a G half diminished chord moving to a G dim7, which then “slides” to an F#7 chord.
- Circle two shows a C augmented chord, spelled enharmonically, resolving to an Ab Major chord.
- Circle three shows an F7 chord used as a German 6th chord, resolving to Em.