Integrate instrument and staff type changes

I'm not so sure the correlation is anything like 99% - I see staff type changes used for purely notational purposes, and the vast majority of instrument changes I see require no staff type change. But it's obviously true for the special case of for changes between pitched and unpitched percussion or tablature. In any case, definitely worth looking at improvements.

I think it's not easy to integrate both because of the many different use cases. But it would be very nice if every Instrument Change automatically adds a Staff Change when really needed (mainly on tablatures), so the composer can then delete it if she/he doesn't want it. Could that be done?

@elerouxx, I believe the work you have been doing to allow all instrument changes will make staff type changes very rare at instrument changes, though there will no doubt be cases where someone will want more or fewer lines on something like temple blocks. Ideally, cases like this could be handled in the staff/parts properties dialog after the instrument change so the staff type change would be unnecessary.

I thought of several ways to integrate staff Type and instrument changes but I found so many obstacles for this: for example, instruments can change in the middle of a measure and staff types don't. And even if we allow that, it would be very hard with the actual code to have more than one kind of staff (1-line, 5-lines etc) in the same measure. Then there is a series of issues on: how do you switch from normal Note Entry to drum mode...

It eventually seemed to me that tying to force a Staff Type change to do what is actually the instrument's job (to know if is pitched, which clefs are allowed, etc) was actually the hard way, and changing that made things start to work better. In my opinion (unless the whole thing is rethought) Staff Type Changes should take care of the visual stuff while Instrument Changes take care of what's functional.

Speaking of that, I was thinking on adding at least these two fields to Instrument Changes, so they start replacing the staff names from that tick on.

As someone who does a lot of instrument changes in symphonic pieces, I'm content to change the instrument names in staff/part properties. In many cases I change the transposition at the same time, like horns written in the bass clef written an octave lower than sounding, which was common in the 1800's. These are actually my most common instrument changes. As you mentioned, you can't do a staff type change mid measure, so a horn that switches between treble and bass mid measure requires a transposition change at the same time.

I have a use case, like changing from a standard tuning guitar to a Drop D guitar tuning. https://musescore.org/en/node/309028
Seems that I cannot do it currently, the tablature is either Standard tuning or Drop D tuning. The Instrument change does not separate the 2 tunings.

(I can create 2 staffs, one for each instrument, but it is not convenient.)

That very use case had come up a couple days/weeks ago I can't find it anymore though...
It seems to be a different issue though

Hmm, actually it might be the one you just linked to

FWIW I have been working mainly on instrument changes and staff type changes. It is becoming clear (to me at least) that most functional data is related to instruments, not the staff type, and this linking of the staff type to determine what clefs, input mode, notation, etc. is allowed turned out as just a limit imposed by design. I mean, the user should not have to choose between a 5-line percussion or a 5-line pitched staff since they are just the same staff, visually speaking. (I believe that limitation was inherited from the need to tell apart tablatures from staves.)

So I created this PR that places Instrument, instead of staff type, in control of what can be done from that point on (i.e. input using drum tools or pitched notes, allowing pitched or unpitched clefs) and so allowing pitched and unpitched instruments regardless of the staff "type".

https://github.com/musescore/MuseScore/pull/6398

That would leave Staff Type Changes basically in control of the visual change of the staff but again, not limiting the functional part of it.

Now about integration - As Marc said, the vast majority of instrument changes on a staff don't require a visual staff change. Even changing to one-line percussion to switch from, say, a xylophone to a triangle, is not a mandatory rule, but an engraver's choice - although is a good practice and a good choice. However, the same can't be said about tablatures, in which obviously you want to change the number of strings to match the new instrument, if different (i.e. from guitar to bass). In this case, integration would be very convenient.

As a side note, In Sibelius, starting from version 6, an instrument change is mandatory to have a visual staff change. This didn't please every user, as you can see around in some forums, since many users just wanted to cutaway parts of the score, or "cutaway to a single line" while the instrument is not playing, or even have the staff lines dissappear to introduce some text or stemless notes for relative pitches/free improvisation, known cases in modern music in which it's messy to have unnecessary instrument changes every single time.
So, we should think on the best way this integration could work from the user's side but IMO not making an Instrument Change the only way to change the staff.
Maybe an instrument change would somehow 'contain' a staff change that you can control from the inspector? I would think on a checkbox "[ ] Change Staff" that would activate the Staff Type Change inspector along with the Instrument Change Inspector.
And the Staff Type Change would still be available as a separate tool.

Relates to #311174: [EPIC] UI/UX issues and suggestions

It could also relate to #311175: [EPIC] Engraving issues and suggestions