Successions

The tritone, composed of exactly 3 tones, is never a problem if it is resolved; obviously, we are talking about successions and therefore melodic rather than harmonic sense. But the attitude is the same in both dimensions (whether vertical or horizontal).

In progression, certain constraints are no longer important because what matters is the progressive scheme that is re-proposed with every "turn" ...namely, in succession. This applies to this specific case you mention, but also to the rules of normal part-writing, which give way to this procedure that is nothing more than the schematic re-proposal of a base cell... and note, that it is managed regardless of the functionality of the chords. So much so that you even go on to harmonize the third degree, etc.

I noticed that you also opened this discussion... perhaps related

http://www.pianoconc...trappuntistiche

... pity it ended up forgotten.

DanielePiano wrote:

I am studying progressions from Piston's harmony treatise; the book speaks of three fundamental progressions:

1) Progressions by ascending motion of a fourth or descending motion of a fifth, or vice versa, of the fundamentals; it is a strong progression with an effect similar to (so says the book) but reduced compared to the V-I progression, which is the strongest progression in tonal music.

2) Progressions by motion of thirds of the fundamentals

3) Progressions by step of the fundamentals

Schoenberg defines the first as strong progressions, the second as weak progressions, and the last as very strong progressions. I imagine Piston does this to introduce you to the main harmonic progressions, in which the movement of the fundamentals is important, to understand the resolutions and tensions that are created.

What can I say, I could talk to you about the counterpoint that lies at its base, but also no; in this case, it is only useful up to a certain point. For now, take these notions as you wish, you will use them later, do not rush