Crazy maths in 5/4 time

• Aug 13, 2012 - 13:00

MuseScore fails to add up the number of crotchets in a bar in 5/4 time. It starts off ok, and then occasionally puts six crotchets in a bar. Or the other trick it does is to create a mysterious one crotchet bar which you can't put back to 5 crotchets again. I could delete the bar if it was just a single stave, but it's in the viola part of a string quintet (and cue viola jokes...). The weirdest thing is that with five staves, at the same place in the piece the bars in some staves are ok and others are not.

It's driving me mad. It gets much worse if you try copying and pasting, then the maths goes completely wrong. Version is 1.2 revision 5470 and is on Windows XP Sp3. I don't remember having this much problem with earlier versions, although maybe I wasn't using 5/4 then.

For example, I cannot persuade the viola part in bar 53 to be anything other than one crotchet in length, although I can insert different combinations e.g. two quavers etc. Also at bar 61 as a result of copying and pasting some bars have six crotchet beats and some five. It's very confusing.

Attachment Size
5-4Example.jpg 396.17 KB

Comments

What has happened, unfortunately, is that your score has become corrupt. Normally, 5/4 really does mean 5/4, with five beats in every measure, but once a score has become corrupt, that can get messed up. And 5/4 is, even more unfortunately, leads to corruption rather easily in 1.X. See #13153: [1.1] cut/paste of empty bar in 5/4 produces corruption. The good news is this is already fixed in 2.0. The bad news is, until then, you just have to be very careful about using copy and paste in 5/4. Or any other time signature in which a full measure rest cannot be represented with a single rest.. Luckily, 7/4 (which I use at least as often as 5/4) doesn't have this problem, since a full measure rest can be represented with a double dotted whole rest.

Anyhow, the best workaround for now - and it's not a great one - is to find out which measures in your score are corrupt, delete them totally (ctrl-del on Windows-style keyboards, not sure about Mac), insert new measures to take their place, and re-enter the music. To some extent you can try to copy and paste the contents of staves that don't seem corrupt from the old measures to the new (I'd use a second temporary score as a "scratch" area), but you do have to be careful not to copy the corruption.

And then, of course, once you've cleaned up your score (or, if the corruption is bad enough, perhaps just re-entered it from scratch, although again, copy and paste from "good" passages should still be OK) you need to be careful not to do any copy & paste of empty 5/4 measures as you continue to work.

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