Looking to do something like this. How would I approach it in the simplest way?
Alternating time signatures gets close, but I want flexibility in how it alternates, so for instance I have a section where I want a 3-bar phrase, consisting of 2 bars of 5/4 and one of 3/4. This pattern would repeat multiple times over, so something like what Tchaikovsky did above would be the cleanest solution. I’ve seen this style used in Debussy and Koechlin as well, the romantics seem to love it.
This is the closest I was able to find, I just did an “interchangeable” signature, but I have to manually change every 3rd and 4th bar. Is this the solution?
If you select 3 bars using the system bar (alt-t), you can copy that across as many bars as you like and the repeating 5/4 5/4 3/4 pattern will be preserved.
Edit: I have never tried doing a 3 bar repeating pattern before, but it does work.
shift-m 5/4 + 5/4 + 3/4 (NB: the spaces are important) will produce a repeating 5-5-3 bar pattern.
To answer one part of your question: alternating time sigs are not “smart.” That is, they don’t actually alternate automatically.
Alternating time signatures in fact do alternate automatically, but that’s strictly for sets of two time signatures. Interchangeable time signatures can have any number of time signatures in the set, but you handle the switching between them, and Dorico automatically hides the time signature changes.