Tatum Thomas Music Theory (Year 3) _ UKZN SYLLABUS _ 2021
Extended Tertial Chords:
Tertial relates to “thirds” (stacking notes to form chords in intervals of thirds)
The basic and most common type of chord is the triad, consisting of two-thirds, one above the root,
and another above the third, which makes a fifth above the root. Adding another third above the
fifth takes us to the seventh above the root. Seventh chords are also common in tonal music, but
further extensions are less common. However, extended tertial chords are much more frequent in
Impressionist music.
*Often one or more of the notes of an extended chord will be omitted. The third and seventh are usually included,
although in 11th chords the third is commonly omitted because of the strong dissonance it creates with the eleventh
(the two notes are a semitone plus octave apart.)
Three Groups:
1) Major Seventh (M7)
2) Minor Seventh (m7)
3) Dominant Seventh (7)
The most common of these are the Dominant extended chords. In these chords, the 9th may sometimes be lowered,
the 11th may sometimes be raised, and the 13th may sometimes be lowered. The chord is then given the seventh
chord symbol with the altered note specified:
The chords tend to stay in root position. Take C 7 b9, if Db was written next to Middle C, it will lose the tertial (third
interval) effect. It will be heard as a minor second instead.
The chord will be named after its highest extension: If the top note is an 11th, it will be the 11th chord.
1
, Tatum Thomas Music Theory (Year 3) _ UKZN SYLLABUS _ 2021
Added-note chords:
When there is clearly a major or minor triad present + one or more other notes = Added note chords
In Impressionist music, added notes are the 2nd and the 6th added to a major triad ( either singly or together )
By adding the 2nd and 6th notes, it reflects the Pentatonic Scale.
4ths are not normally added. It creates a strong dissonance when paired with minor 2nd and 3rd of MAJOR TRIADS.
It is found more commonly with minor triads, where it forms a major second with the notes on either side of it.
The second is the same letter name as the ninth, it’s just a second an octave above. When the ninth appears
without the seventh, it is sometimes identified as an added note rather than an extended tertial chord.
*Note that the symbol must specify an “added note” ( C9 would imply a dominant seventh with the ninth as an
extension.)
2
Extended Tertial Chords:
Tertial relates to “thirds” (stacking notes to form chords in intervals of thirds)
The basic and most common type of chord is the triad, consisting of two-thirds, one above the root,
and another above the third, which makes a fifth above the root. Adding another third above the
fifth takes us to the seventh above the root. Seventh chords are also common in tonal music, but
further extensions are less common. However, extended tertial chords are much more frequent in
Impressionist music.
*Often one or more of the notes of an extended chord will be omitted. The third and seventh are usually included,
although in 11th chords the third is commonly omitted because of the strong dissonance it creates with the eleventh
(the two notes are a semitone plus octave apart.)
Three Groups:
1) Major Seventh (M7)
2) Minor Seventh (m7)
3) Dominant Seventh (7)
The most common of these are the Dominant extended chords. In these chords, the 9th may sometimes be lowered,
the 11th may sometimes be raised, and the 13th may sometimes be lowered. The chord is then given the seventh
chord symbol with the altered note specified:
The chords tend to stay in root position. Take C 7 b9, if Db was written next to Middle C, it will lose the tertial (third
interval) effect. It will be heard as a minor second instead.
The chord will be named after its highest extension: If the top note is an 11th, it will be the 11th chord.
1
, Tatum Thomas Music Theory (Year 3) _ UKZN SYLLABUS _ 2021
Added-note chords:
When there is clearly a major or minor triad present + one or more other notes = Added note chords
In Impressionist music, added notes are the 2nd and the 6th added to a major triad ( either singly or together )
By adding the 2nd and 6th notes, it reflects the Pentatonic Scale.
4ths are not normally added. It creates a strong dissonance when paired with minor 2nd and 3rd of MAJOR TRIADS.
It is found more commonly with minor triads, where it forms a major second with the notes on either side of it.
The second is the same letter name as the ninth, it’s just a second an octave above. When the ninth appears
without the seventh, it is sometimes identified as an added note rather than an extended tertial chord.
*Note that the symbol must specify an “added note” ( C9 would imply a dominant seventh with the ninth as an
extension.)
2
