Repeats don't nest

FWIW, logical as nested repeats may seem to some, they are virtually never notated that way, because it is virtually 100% likely a human musician won't be be able to follow the intended roadmap any better than MuseScore does. Not saying MuseScore shouldn't add such an option anyhow eventually as a playback enhancement, but I strongly advise people not to actually use any such feature in music meant for human consumption. Train wreck waiting to happen.

And since this not something that is normally notated, I wouldn't call the lack of this feature a "bug".

The way you get it played correctly is simply to write it all out. Sometimes, it is possible that sufficiently clever use of DS et al will get the job done. In this case, a segno at A, a DS after C with the notation "take repeats", would do the job, although it would kind of odd to reach that DS a second time, so you might have a "to coda" somewhere within C, and repeat the last bit of C as the beginning of the coda, followed by E.

As you have it, though, my eye sees unmatched repeats, and as a musician I have no earthly idea where the closing repeat after C is meant to go back to. The computer scientist in me eventually figures out you probably meant to go back to the opening repeat before A, but again, that is not normally done.

If I were to offer a suggestion as to what MuseScore "should" do in the case of mismatched repeats like these, I might suggest the "correct" answer would be S A BB C followed by an error message about mismatched repeats that would either halt playback or else go on to E.

Musicians will most probably get confused if nested *repetition bars* are used, but I (myself) am not looking for nested repetition bars: any different kind of notation would do, and would even be much better. For instance, something like a single pair of repetiton bars inside a countable "dal Segno" followed by a coda.

Think of a song with a prelude, three stanzas each one with a repeating line, and a coda. The score might first include the prelude without text, next (set apart from this) the music of a stanza with its single pair of repetition bars and three lines of text one below the other, and finally the coda (again set apart). I see no reason of why a musician should get confused with that; he would know quite well that the stanzas have to be sung (and therefore played) one after another.

Yes, repeats within a DS are very common, although it is by no means certain whether the repeats should be taken during the DS or not. Often in such cases the text of the DS itself contains instructions like "take repeats" or "no repeats" in order to eliminate ambiguity, and MuseScore should have a way of modeling that as well. FWIW, in my circles at least, the usual convention is that you *don't* take repeats on a DS unless specifically instructed to, but I'd never want to leave that up to chance.

I agree that, since MuseScore is a notation application and notation has priority over midi, the correct notation of this would be:

S |: ABBC :| E

The only thing I would request as a feature is that repeating barlines' number of repetitions could be set in the repeat properties, if this hasn't been implemented yet. Typical in songs with more than 2 lyrics for the same estrophe.

I was looking for the bar properties, not in the measure, sorry.

So... There you are!

Unfortunately it's that way musicians write music, only use 1 level of repeat bars and then other simbols (D.C. al fine, alla coda, al signo, and so on).

I am happy to read in #6 by Marc Sabatella that
"repeats within a DS are very common"
and that
"the text of the DS itself contains instructions like 'take repeats' or 'no repeats' "

So let us agree with elerouxx in #8 that
"MuseScore is a notation application and notation has priority"
and thus promote the playback implementation of repeat instructions that seem to be common!

Nothing more - but nothing less :-)

I got into this nested repeats issue and found it to be very interesting. By reading https://www.reddit.com/r/musictheory/comments/1bnovd/why_dc_al_fine_and…

i conclude that there are indeed different use cases for different groups of sheet music readers and i do understand, that musescore hast to focus on some general cases especially on notation and not playback and i love the things i can do with it. It is a great software.

Here are two contrary use cases i found out about:

1. The live musician, getting the sheet 5 minutes before performing
   The instrument player just wants to play the sheet and he has no time to study or remember multiple nested repeats.
   In this case it is better to have less repetitions :| or jumps in trade of more sheets with more copy and paste parts in it.

2. The amateur choir director who has some time to explain and pratice which parts are sung when and how often and how the jumps are performed
   In this case it is better to have less copy and paste parts, to safe paper. If there are some unconventional nested repeats the director will explain and practice it until the choir performs :)

I found myself trying to set a pop song (https://musescore.com/user/10920366/scores/4364156) with nested rests and i wanted to have musescore play it exactly the way i want without using any more copy and paste parts. But now i realize that this special case is not a reasonable domain for musescore. In fact the notation seems cristal clear for me and the playback is not that important.

Since Bach's time, even repeat signs ( bar :|| ) were placed according to certain rules.
At the moment there are those who want to use two separate signs in a 4-measure passage.

In a small form, such as AABA; the bar repeat signs (bar) can be used for the first two A's. Which is usually two measure voltas (1. and 2.) at the end.
For all other short repeats, either write them as they are or use short cuts. as %, %%, %%%%.

And also, if possible: a repeat sign (bar) should not go outside the sections (or combine different sections) of the Form. (A, B, C, Coda)
So it is not logical to put a repeat sign (bar) at the end of a 32-measure (AABA) form, and ask for the piece to be played from the beginning.
For such cases, there are specially prepared texts: like "D.C. "D.S."

Repeats(bar) can not be nested.
But: Those who want to use the note writing software like a sequencer can write the following. But how does the musician interpret it? (see picture) Note. It is not written in a certain order. Priority can be changed according to the person.