Finding Thirteenth Chords On The Keyboard

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Of all the common chords, thirteenths are the biggest - and the hardest to visualize on the keyboard. Any given type of thirteenth, for example, makes twelve different visual patterns of black and white keys, one for each root along the chromatic scale. Each pattern, of course, can be individually memorized. But such learning by rote is tedious. Here's an easier way to learn thirteenth chord patterns, a way that requires only the recognition of Major and minor thirds or the recognition of Major and minor triads.

* Major and Minor Third Recognition

White key Major thirds always enclose two black keys; white key minor thirds enclose only one. Example: Major 3rds F to A, C to E, G to B and Minor 3rds: B to D, A to C, E to G, D to F

Black key Major thirds always enclose another black key; black key minor thirds do not.
M 3rd: Gb to Bb and mi 3rd: Eb to Gb and Bb to Gb

Black and white key Major thirds always enclose two white keys; black and white key minor thirds enclose only one. M 3rds (white over black): Db to F, Ab to C, Eb to G, Bb to D. Then we have M 3rds (black over white): D to F#, A to D#, E to G#, B to D#

mi 3rds (black over white) F to Ab, C to Eb, G to Bb and (white over black) Gb to A, Db to E, Ab to B

* Thirteenth Chord Structures

Alternate letters along the musical alphabet specify chord components above the root. As the next example shows, thirteenth chords contain all seven:
1 3 5 7 9 11 13
C E G B D F A

Here's an easier way to learn thirteenth chord patterns. Just spot the Major and minor triads.

* The Model Thirteenth Chord Types

Among all the types of thirteenth chords, three predominate. The first type, the Major thirteenth (#11), alternates Major and minor thirds upward:
CM 13(11#) = C to E (M3), E to G (m3), G to B (M3), B to D (m3), D to F# (M3), F# to A (m3)

The second type, the minor thirteenth, alternates minor and Major thirds upward, just the reverse of the first, Cm13:
C to Eb (m3), Eb to G (M3), G to Bb (m3), Bb to D (M3), D to F (m3) and F to A (M3)

The third type, the Dominant thirteenth(#11), groups its inner thirds in orderly pairs. It encloses two successive minors then two successive Majors between its bottom Major and its top minor: Major, minor-minor, Major-Major, minor. C13 (11#):
C to e (M3), E to G (m3), G to BB (m3), Bb to D (M3), Gb to A (m3)

So the three types also look like stacked triads: Major-Major-Major, minor-minor-minor and Major-minor-Major. Altered notes produce additional types. and there's a way to find all the possible thirteenth chords types. Either position of the third (Major or minor) combines with any position of the fifth (Perfect, augmented, or diminished) to yield six types. Then, mixing in various positions of the seventh, ninth, eleventh, and thirteenth multiplies the number of possible types to more than two hundred! lol

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has a great theory instructional book for you that you will want to have and refer to it often.
Music Theory book

All the best,
~ LadyD