Originally Posted By: Mark Hayes
Re: Stopping at 13ths –

Take a 6th chord. Push that 6th note up and the chord becomes a 7th.

What happens if you do that to a 13th chord? What do you call it, if not a 14th?
(Screenshot shows what I think would be a "C dominant 14th")

I realize you have to stop somewhere, but I'm curious about this limit. Maybe 13 is just bad luck for all numbers above it.

https://en.wikipedia.org/wiki/Thirteenth


OK, looking at that chord, I think I've answered my own question. Partially.

A dominant 13th is adding a new pitch class to the chord, like A in the key of C. That pitch class is not present in the chord below it.

However, a "dominant 14th" just doubles the 7th, like Bb in the key of C. That pitch class is already present in the chord below it, so you're not really adding anything.

Of course, you could raise the seventh to a B and keep the 14th as a Bb, or raise the 14th to a B ...