The trill speed and its variations

Your idea

I propose to implement a system in MuseScore Studio in which it would be possible to indicate a change in the intensity of the trill line itself in order to reflect the changing speed.
The notation itself involves specifying the technical instructions themselves, as well as changing the intensity of the trill line. This could serve as a good visual understanding for the performer, who would not have to guess how to play it.

I also suggest adding an option in the trill Properties, in which you could specify the playback speed (and according to 3 components: start / middle / end). It is even better to have a special pop-up for this, which would allow you to accurately determine the speed change for the trill.

On top of the trill line itself, the user should be able to specify technical instructions, such as "slow, accel.", "rit.", "start trill slow and accel.", etc. This is necessary primarily for clarity, for understanding, since a wavy line with alternating intensity without following written instructions may be unclear.

Problem to be solved

I think first of all it would help to describe it with sound. At the moment, there are no settings for trill speed in MuseScore Studio. Therefore, in both MS Basic and Muse Sounds, trills sound at a single speed, regardless of what the user's real intentions, style, and genre of the score may be.
Moreover, if trill playback works quite straightforwardly in MS Basic, then in Muse Sounds it works in different ways. For example, I'll show you how the same instrument sounds at the same tempo in MS Basic and Muse Sounds:

https://github.com/user-attachments/assets/a81a0a2e-1016-43f5-97e6-89e49480ff83

Did you hear the difference? In Muse Sounds, it sounded with a huge delay at the beginning, as if the player had noticed the trill late.
Due to the fact that MuseScore Studio does not have a system that can control the speed of trills, the MuseSounds team creates trill samples the way they like.

As for the change in trill intensity.
At the moment, this feature is not available in MuseScore Studio. But you say, "What about the text designation?" Okay, let's take a look at this.
First, the text line intersects with the trill line. This is unacceptable.

Secondly, you cannot change the style of the text, reduce it, or compose it in two lines. Because of this, the text may simply not fit in the appropriate place. Yes, it can be done without a text line, it can be done using plain staff text, but then it will become ambiguous where exactly the trill speed change should begin and end.

Prior art

Dorico has a system that allows you to do this. You can indicate different speeds for trills, including indicating a change of speed within a single trill, by changing the height and frequency of wiggles in their extension lines.

BUT there is one drawback. Only the initial and final speeds can be changed there. It's not bad when the trill is short and it doesn't make sense to have more settings. But when the trill is not short and the tempo is slow, that's when more adjustments may be needed. Therefore, I suggested at the very beginning to be based on at least 3 components: start / middle / end. Probably so that you can create something like this:

Additional context

No response

Checklist

• This request follows the guidelines for reporting issues
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The issue identifies trill Properties and trill playback in MS Basic and Muse Sounds, but names no files, tests, or entry points. Start by locating those areas and clarifying the proposed start/middle/end speed model and notation behavior. Done would require an agreed scope for playback and visual representation.