19a Discussion - Extended Tertian Harmonies and Non-chord Tones

“When do we know that something is extended harmony?”

• If a pitch can be explained away as a Non-Chord Tone, that is the best option.
• If a pitch is crucial for the melody, heavily emphasized, or can’t be explained any other way, then it must be functional.
• Something is considered an extension when it can fit in to a stack of thirds beyond the seventh.

Nomenclature:

In tertian harmony (based on stacks of thirds), the extended tones are 9ths, 11ths, and 13ths.

When labeling with lead-sheet, these numbers are assumed to represent diatonic intervals (in terms of major) above the root. However, the 7th requires special indications.

G⁹

• A letter and number on its own implies a dominant seventh
• This chord would be spelled: G, B, D, F, A

Gmaj⁹ or G∆⁹

• The maj/∆ is required to indicates a major seventh. This does not affect the quailty of the 9. The 9 is still assumed to be diatonic
• This would be spelled: G, B, D, F^#, A

G¹¹ or G¹³

• Like with the 9, these chord will include a dominant seventh
• Many players will also assume that the 9 is included!
• So, these would be spelled:
• G¹¹: G, B, D, F, A, C
• G¹³: G, B, D, F, A, (C), E

Altered Extensions:

• To alter the quality of an extension, you separate it from the 7 like this: G^7(b9)
• This would be spelled: G, B, D, F, A^b
• Other common altered extensions include: G^7(#11), G^7(b13), or G^7(#13)

Isolated Extensions:

• If you don’t have a seventh, but you do have higher extensions, you can leave the 7 out of you lead sheet like this:
• G ^{add 9} or G ^{add #11}

Minor:

• The same rules for sevenths and extensions apply to minor chords. The only change is that the triads are minor.
• Since leadsheet is not based of the key signature, all extensions are assumed to be major intervals above the root.