Lucky Thirteenth

Today being Friday the 13th, I thought this might be an appropriate topic. However, if you suffer from triskedekaphobia (fear of the number 13), you may want to skip this one.

On the other hand, if you’re looking to get some real “hep” sounds without a lot of effort, read (and listen) on…

I first encountered the 13th chord in high school during a jazz band rehearsal, reading the piano part. When I asked the instructor what exactly that meant, he simply said it was a chord with “everything.”

Indeed it is:

Now, in “legit” and film music, this harmonic structure is often sounded in just this way (check out the 1981 movie Windwalker to hear some examples from Merrill Jensen’s score). However, in jazz and theater music, the 11th is almost never used – and the 7th is invariably flatted.

At seventeen, I learned the truth – about thirteenth chords, anyway – and how real jazzers actually handled them. This information was imparted to us  during a summer “jazz camp” I attended at a Southern California community college back in the 1970s, demonstrated as part of a “I-IV-I” progression:

Now let’s drop it an octave add a bass line so it makes aural sense.

Here is the full 12-bar “blues” progression, using 13th chords.

Notice in both the visual and aural examples that only four notes are being played in the treble accompaniment: the third, seventh and ninth, which correspond to the “shell” I referred to in the previous post, and of course, the thirteenth.  And, by using these four notes in different inversions, we avoid having the voices leaping all over the place – in accordance with good practice when it comes to guide tone lines.

I’ll elaborate on this more in the next post. In the meantime, here’s something for novices to ponder: why isn’t there a “fifteenth” chord?

Feel free to leave questions,  music-related comments and/or links to your music-related blog (but please spare me the travel bargain and viagara drivel – it wastes my time and yours, since such comments are immediately deleted and people posting such material banned).


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About KJ at Guide Tone Lines

KJ McElrath earned his Masters degree in Music Theory and Composition from Central Washington University. Composer of several works for big band, wind ensemble and orchestra, which can be heard at I perform a cabaret act with Athena McElrath as McElrath Cabaret, which you can find at
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