====== Extended Tertian Harmony: 9th, 11th, and 13th Chords ====== > **Concept:** By adding additional thirds to //triadic// harmony, one can create 9^th, 11^th, and 13^th chords. //Note:// It is common - and often necessary - to omit some notes of the chord, especially in four-part writing. Examples: {{music_theory:extended_tertian_harmony_-_common_constructions.png?800|}} Function: Most 9^th, 11^th, and 13^th chords are dominant chords (V⁹, V¹¹, V¹³), though in reality any triad can be extended. Other common non-dominant extended tertian chords are based on I and IV. Stacking extra thirds onto a triad does NOT change its original function! For instance, a V¹¹ chord still typically resolves to I (or i), and a ii⁹ chord still typically resolves to dominant harmony (V). Position: Extended tertian chords are usually found in root position, as they tend to lose their identity when inverted. Secondary function: 9^th, 11^th, and 13^th chords can also occur as [[secondary dominants]]. Analyze this progression: {{ :music_theory:extended_tertian_harmony_-_secondary_dominant_example.png?700 }} {{ :music_theory:extended-tertian-harmony-example.mp3 | :music_theory:extended-tertian-harmony-example.ogg }} ===== Summary ===== ^ Chord ^ Typical Members Present ^ Voice-Leading Guides ^ | V⁹ | R, 3, 7, 9 | 9^th and 7^th resolve downward to the 5th and 3rd of the tonic triad. | | V¹¹ | R, 3, 7, (9), 11 | 11^th is retained as a common tone with the tonic triad. | | V¹³ | R, 3, 7, (9), 13 | 13^th is usually in the highest voice and resolves downward to the tonic.\\ If the tonic triad contains a chordal 9^th, the 13^th could resolve downward to the 9^th of I⁹. |