Which mode if a melodic-thematic fragment is chromatic?

I looked at the subject of the fugue. I'm not entirely convinced that all the notes you mentioned are "core notes," but regardless of everything, let's think about the descending scale "G# G F# F E." It might be cliché to say, but the fact that it is chromatic characterizes it more as tending towards minor than towards major. The premise is that, anyway, one can never know for sure. The key of a piece must be asserted and confirmed, and without a clear cadence, one is in an ambiguous situation. That being said, in a contrapuntal logic—that is, considering the melodic lines as autonomous carriers of a modal-harmonic sense—the final descending semitone leap "F-E" can be understood as a clause, a "melodic cadence" let's say, and being a Phrygian clause, it instinctively brings us back to a Phrygian mode. Which, by "analogy," is closer to a minor scale with a Neapolitan second.

Looking at the subject, everything is much simpler. The fact that in every measure there is a leading tone that is then lowered by a semitone when it is part of a descending movement makes everything blatantly minor. Then, clearly, all of this during the composition of the piece, or the reharmonization of the fragment, can be subverted and reinterpreted.

I agree with Thallo!

I'll just throw this out there, the minor scale is better suited for inserting chromaticisms precisely because many nuances already exist congenitally with the alteration of the sixth and seventh degrees. If you consider that even the fourth can be raised (even in the major mode, obviously)... the game is won...

thallo wrote:

I looked at the subject of the escape lab. I'm not entirely convinced that all the notes you mentioned are "core notes"

Interesting Thallo, which ones would you indicate?