Pickup measure should be automatically reflected in final measure as complement

I believe you are correct but the reality is that lots of music is scored without adhering to this convention.

It's *not* a question of one way being "right" and one being "wrong" - it's really just two different but equally valid conventions that both have a long and well-established history behind them. And then a question of to what extent it makes sense from a technical and usability to technical and usability perspective to try to *automatically* support the convention of subtracting beats from the final bar of a piece with a pickup.

I'm not a musicologist, but my understanding based on what I have learn and my reading of many different types of scores published over the last several centuries is this:

The convention of subtracting pickup beats (aka anacrusis, especially in the UK) from the final measure was most in vogue in the 17th-19th centuries. It was especially useful for short dance pieces (minuets, etc) to allow the musicians to easily repeat the whole form to extend the dance. Also, for hymns with multiple verses all printed below a single system of music, for the same reason. Basically, any piece of music where you might be inclined to repeat the entire form. Some publishers went ahead and also used this convention for other types of pieces, others did not. As longer and more complex pieces came to be published more regularly - consider the possibility of time signature changes within the piece! - the usefulness and wisdom of this particular convention diminished such that more and more publishers stopped using it in any but the shorter / simpler forms for which it was originally useful. And many publishers eventually stopped using it even for those shorter / simpler forms, choosing instead to represent even hymns with complete last bars that repeat the pickup - perhaps rendered smaller or in parentheses to indicate that it won't be played after the final verse, or perhaps with voltas.

Today, you see many publishers *never* using the convention of subtracting pickup beats from the final bar of a piece. Others use it on the type of music - short dance pieces, hymns - for which it originally made sense, but not on longer / more complex pieces. Some use it for reprints of pieces if they were originally published using that convention, but not for new pieces. Some publishers use this convention in their classical series but not their jazz or pop series. The bottom line, it is *far* from being universal today, and in fact, I'd say the majority of newly published music does *not* use this convention, although I will certainly concede that one's impression of what is most common today is largely affected by geography, style preference, etc.

Anyhow, just because the convention is an older one that may or may not be slowly dying out doesn't mean MuseScore shouldn't support it. And of course, it *does* support it - you just have to make the adjustment to the final bar manually. So the question is, should MuseScore support an *option* (because many users won't want to use this convention at all) to handle this more automatically.

And, indeed, the subject of implementing such an option for MuseScore has come up before, several times. There are definitely technical issues to deal with, though. There is the matter, as mentioned here already, of handling the appending of new bars (surely a very common case, as very often you would not know before starting a piece how many measures you'll need). There is also the question of what happens if you change your mind and alter the length of that pickup measure, or remove it entirely. And, as I mentioned above, what about pieces that change time signature over their duration? If a piece starts in 5/4 but ends in 6/8, and the pickup is two quarter notes in 5/4, exactly what do you propose doing to that final 6/8 bar to compensate?

So, given the fact that this convention isn't all that relevant to a great deal of music, the fact that many people have no desire to ever use it, the fact that many people who haven't specifically studied 17th-19th century classical music may have never even heard of it (since many modern publishers and instructional books no longer use it), and the fact there are technical issues with trying to make it work automatically - my opinion is that current approach is just fine. That is, those people who are aware of this historical convention and who are making a conscious choice to continue using it can do so by manually shortening the last measure.