Text: FUNCTIONAL HARMONY

Hi Modale, I have a doubt.

How does functional harmony include "chromatic" as a subcategory if it is known to everyone that functions are almost strictly tied to the key?

Perhaps through Riemann and subsequent modifications/integrations?

Thank you if you can clear up this doubt for me.

Here for example the subdominant was discussed, the references are very clear to a tonal logic

www.pianoconcerto.it/forum/index.php?/topic/632-contraccordo

There are functions related to tonality, functions related to modality - such as modal gravitation - and functions related to chromaticism which, being by nature non-diatonic but intervallic, allows for functions related to intervals. Obviously, the functions of one category do not operate in another category. I understand that the answer is laconic, but an entire text would be needed to answer your intelligent question. The text ....is there.