# Convert from/to compound meter

• Jul 27, 2015 - 17:42

As far as I know currently there is no any way to convert score from/to compound meter (with saving measures). For example, convert from 4/4 with triplets to 12/8. Essentially compound time is a way to simplify notation, like elimitating triplets from 4/4.

Unfortunately, I found no way to make this conversion automatically. The only solution is manually rewriting whole score! Even copy-paste doesn't work.

It's not a such big deal to make the conversion automatically because in fact this is just multiplying every note's duration by a constant. E.g. to conversion 4/4 -> 12/8 is multiplying each note to 3/2.

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12-8_equals_4-4_drum_pattern.png 5.97 KB

There are similar requests to handle doubling and halving of note values - rewriting four quarters in 4/4 as four eighths in 2/4, for example. Handling conversion of tuplets and compound meter is unfortunately considerably more complicated to to how they are implemented - and consider the possibility of scores containing duplets within the compound meter, or, quintuplets, etc - but some of those problems have to be solved even to make double time / half time work.

This *is* on the list of thing of things being considered for 2.1, but it's not really clear how it should work. One thing that would help a - a lot - is for people to brainstorm ideas for how some of these sort of corner cases should be handled, also propose UI ideas. Naively, I might hope for a small number of new menu items under Edit / Tools - half, double, convert to compound, convert to triplets - with no dialog box required. Somehow, I doubt it will turn out to be that straightforward, though.

In reply to by Marc Sabatella

I would like something like this: when I set new meter from the palette (for a whole score, or selected measures), dialog box appears with options:
1) just change the meter without change notes' durations (this is current behaviour)
2) convert to new meter and fix notes' durations (multiply by new_meter/old_meter)

In reply to by Vasya Petrova

No, please don't pop up a dialogue box whenever a new time signature is inserted. Sometimes I deal with tunes that change time signatures very frequently, possibly every measure...I will never get through inputting the song!

Since converting prewritten notes to new meters is likely to be a user action that occurs infrequently, I think it is better left to a plugin or other option accessed from the top menu.

In reply to by Vasya Petrova

But even if I do already have notes already written and am putting in a new time signature, all that means at the minimum is that I'm changing the time signature, nothing more should be implied. Musescore's current behavior where it shifts the barline around is valid and just fine and is expected, so I think should be default without any annoying popups. And this indeed is usually what I want when I'm sticking in a new timesignature.

What you are talking about is more specifically called "metric modulation" //en.wikipedia.org/wiki/Metric_modulation I believe. I be up for having "metric modulation" be implemented as a plugin or maybe have a special option to set if user always wants their insertions of time signatures to mean a metric modulation. The user could even be presented with an option in the "metric modulation" dialogue to switch tempo by corresponding ratio as well as just convert metrics.