Numerical Analysis of Chords
How to figure out chords on the guitar. (Part Three)
9th’s, 11th’s, 13th’s and other extended chords.
Continuing from parts "One and Two", let's take a look at the list of structures needed for "Five note" or extension chords.
You can compare the original "first octave" structures with the new "second octave" structures to find that some of the Roman numerical placements have been altered to higher numbers: "ii = ix", "II = IX", "iii = #IX", "IV = XI", "v° = #XI", "VI = XIII".
First octave positions
Second octave positions used for extended chords. Note the corrisponding note positions in the first chart, and how they are replaced with higher numbers in the second chart.
Here are the most common structures for “Extended” chords.
* 6th’s and 9th’s:
6th-7th = I - III - V - VI - vii
6th-9th = I - III - V - VI - IX
Minor 6th-9th = I - iii - V - VI - IX
(Dominant) 9th = I - III - V - vii - IX
Minor 9th = I - iii - V - vii - IX
b9th = I - III - V - vii - ix
Minor b9th = I - iii - V - vii - ix
#9th = I - III - V - vii - #IX (The "Jimi Hendrix" chord)
Major 9th = I - III - V - VII - IX
Major-minor 9th = I - iii - V - VI - IX
Major b9th = I - III - V - VII - ix
Major-minor b9th = I - iii - V - VII - ix
Major 7th#9th = I - III - V - VI - #IX
* "Alt" Chords:
7th b5th #9th = I - III - v° - vii - #IX
7th b5th b9th = I - III - v° - vii - ix
7th #5th b9th = I - III - V+ - vii - ix
7th #5th #9th = I - III - V+ - vii - #IX
* 11th's and 13th's:
(Dominant) 11th = I - III - V - vii - IX - XI
Minor 11th = I - iii - V - vii - IX - XI
(Dominant) #11th = I - III - V - vii - IX - #XI
Minor #11th = I - iii - V - vii - IX - #XI
Major 11 = I - III - V - VII - IX - XI
Major-minor 11 = I - iii - V - VII - IX - XI
Major #11 = I - III - V - VII - IX - #XI
Major-minor #11 = I - iii - V - VII - IX - #XI
(Dominant) 13th = I - III - V - vii - IX - XI - XIII
Minor 13th = I - iii - V - vii - IX - XI - XIII
13th b9th = I - III - V - vii - ix - IX - XIII
13 #11 = I - III - V - vii - IX - #XI - XIII
Minor 13th #11 = I - iii - V - vii - IX - #XI - XIII
Major 13th = I - III - V - VII - IX - XI - XIII
Major-minor 13th = I - iii - V - VII - IX - XI - XIII
Major 13th #11 = I - III - V - VII - IX - #XI - XIII
Major-minor 13th #11 = I - iii - V - VII - IX - #XI - XIII
How many of these types of chords you will use in everyday practicality is debatable, but they do exist mathematically. Many of the strange structures that are less-pleasing to the ears are considered "transitionary". In other words, they need to be in context with the chord structure of the song to make harmonic sense.
Also, remember that the guitar only has six strings. This means that not all notes in the structure will be used in the actual chord structure. Most extended chords will eliminate the need to use all of the highe rnumbered positions, and only use the notes needed to fit the name of the chord. In other words, any “13 chord” will never use all seven notes to make the chord - not even on a piano.