Tremolo causing corruption

• Nov 25, 2011 - 10:38
Type
Functional
Severity
S2 - Critical
Status
closed
Project

I seem to keep getting corrupted files when I create tremolos between a chord and a single note. Jojo-Schmitz could not reprduce the problem on the basis of what I had posted and screen shots I attached (http://musescore.org/en/node/13786#comment-47643), and suggested I should post exact details plus a MuseScore file here. So here goes.

I created a new MuseScore file, called Tremolo problems, with a violin and a piano part.
Step one, input the right-hand piano first bar, a C major chord and a single G, as minims. Select bar, double-click on tremolo symbol in palette. Tremolo with breves/whole notes was created, but minim stems remained.
Step two, input first bar left hand as minims, select bar, double-click in tremolo palette, perfect tremolo created.
Step three, copy bar one (both hands) and paste into bar three.
Step four, type Ctrl+R to extend bar three notation into bar 4.
Step five, add an arbitrary fiddle part.
Step five, save file.
Step six, reopen file.
Corrupted result shown in attached screenshot, and Musescore file itself is attached to this post (not resaved after screenshot was made).

Any ideas?

Attachment Size
Tremolo screenshot.jpg 213.09 KB
Tremolo problems.mscz 1.79 KB

Comments

My original post attracted no response, but the problem with tremolos has not been cured in version 1.2. Essentially, I first create a simple two-note, whole-bar tremolo (input two minims, select both and double-click the trem. symbol). If I try to copy and paste the bar to successive bars, or to use the R command to extend it to successive bars, the result is inevitably an inaccurate version of the tremolo, with the first note correctly shown as a breve and the second as a minim. Bars of this type are clearly badly corrupted. Any manipulation other than deleting the entire (incorrectly drawn) bar results in bugs such as bars that accept no note input, or have fewer beats than indicated in the time signature. This seems to be a pretty serious bug; I'm surprised no-one else seems to have run into it or commented on it!

+1 In 1.2, when I enter a half note chord and a note and connect them with tremolo, the result is incorrectly breve notes. I also agree that this is a major bug.

I think you are confused as to how tremolo is supposed to work. As far as I can tell, there is no bug in creating tremolos - if you try to connect two half notes (minims), it is *supposed* to turn them into whole notes (semibreves). The measure is *supposed* to look like it has two beats in it; that is how tremolos are notated. If you want two half notes (minims) connected by a tremolo, the way to do that is to enter them as quarters (crotchets). You ebter the actual number of beats you want to hear; MuseScore automaticaly turns that into the proper tremolo notation when you add the tremolo.

The bug only exists if you then try to copy the measure containing the whole note (semibreve) semibreve tremolo to another measure; the result then looks like a whole note (semibreve) connected to a half note (minim). It's u fortunate, but the workaround is simple - do not copy and paste such measures.

Title Problem with tremolo causing file corruption Tremolo causing file corruption

Does this problem apply in the nightly builds?

I ask because focus is now on 2.0 (which will be released later this year).

It appears to be fixed in the trunk - at least, I could not reproduce the specific symptom described here (copy and paste of a measure containing a whole note tremolos).

And to be clear, even in 1.2, as far as I can tell, the bug does only affect copy and paste of whole note tremolos (at least in 4/4 time). Other tremolos copy and paste and just fine.

I have 5498 installed, and the bug did not appear in that version.

BTW, at first I was thinking that it was the appearance of the pasted measure that was messed up in 1.2, but no, it really is corrupted - attempted to delete the measure affects the contents of the next, etc.

I'm glad to see this issue is being picked up at last. For me it's been a major headache, working with musical theatre scores that teem with tremolos. The discussion is still missing points. Let me list them carefully. I've attached a JPEG of two screendumps (you'll see why posting the file won't necessarily help clarify).

1. Create a tremolo with a single pair of notes: I used minims in bar 1 of the attached (top part) then selected the notes and double-clicked the 'three between notes' icon in the Tremolo palette. The resulting tremolo is correct but imperfect: the 'three between notes' stripes are positioned towards the left note; they should be central. This can be cured by hand: double-click the stripes and move them to the right with the arrow key. NB, this means more manual input than should ideally be needed. It can become very time consuming.
2. Now copy and paste the tremolo (bars 2 and 8, top). The first note remains a breve, the second becomes a minim. This has already been discussed above. The work around is, as Marc Sabatella suggests, not to copy and paste. But that's a serious loss of function for the user! Yet more time wasted doing manually what the software should handle on autopilot.
3. Create a tremolo with a chord and a note (bar 4 top). Now you have a real mess. The breves have a kind of double-stem, one on each side. Copy and paste (bar 5) and you lose the double-stem effect and revert to the bug already much discussed.
4. Save the file and reopen it. Oh boy! Look at the total disaster in the bottom half of the JPEG. A barline has shifted incorrectly at bar 4, an extra barline appears at the end of the stave. If anyone can tell me this stuff does not amount to a major bug around creating tremolos, I throw in the towel. I've ended up creating empty bars in my scores and writing in the trems by hand on print-outs. Not much of a recommendation for a program that in most aspects is superb! Just in case you care, once the score is messed up by the tremolo bug as shown in the second example, it becomes impossible to enter notes accurately. Measures behave weirdly, unpredictably acting as if they have fewer beats than indicated in the time signature. Essentially, the only safe way to handle tremolos is never to write chord trems and never copy and paste a trem.

Attachment Size
tremolos.jpg 407.98 KB

Actually, posting the MSCZ file might have helped at least with respect to one of your points: I am not sure I understand bar 4. Did you change that one to have have an actual time signature of 8/4, and then enter 2 whole notes? If so, why did you leave that step out of your description? You seem to be implying that simply creating a tremolo involving chords somehow causes a problem, but I have been unable to reproduce it. I *was* able to get something that looks like what you describe by erroneously selecting the entire measure before double clicking the tremolo symbol in the palette, rather than just selecting the first chord as one is supposed to. While that probably shouldn't have failed as badly as it did, it does work if you do it correctly. So I don't see any significant bugs involving tremolos with chords overall.

As I already said, it does appear that copy and paste of certain tremolos - eg, whole notes in 4/4 time - cause corruption. And as I also already said, it appears that bug has already fixed. So I am not sure what you mean about "throwing in the towel" here. You've reported a bug, and it has already been fixed. Is there something else I am missing?

I do agree the default position of the tremolo symbol is less than ideal, and that does appear to still be a problem in 2.0. It's no worse than the less-than-ideal default positioning of a lot of other symbols, which is something I'd like to see addressed overall, and there has already been discussion of that topic, but you might as well file an issue for this with respect to tremolos specifically.

As for working around the copy/paste bug in 1.2 - the only bug I can see from your description - it isn't actually very difficult. If you do find yourself with a lot of whole tremolos you need copied, just do the copy *before* adding the tremolo. Then add the tremolo to all measures at once, by ctrl-clicking the first note/chord of each pair then double-clicking the tremolo symbol in the palette. Yes, obviously, a few more clicks than necessary, but again, the bug is already fixed for the next release.

Hi Marc,

Thanks for coming back on this one.
No, I didn't change time signatures at all. I've made another one. Here's the process in precise detail with a repeat performance. By the way, I'm using the computer (type) keyboard only because my midi keyboard is away elsewhere right now: I usually input via midi; it makes no difference to the problem.
So, a new file: tremolos2. First I created a 4-bar C major piano score with 4 bars (does the instrument have any significance?). Then I added notes via the computer keyboard. Two Cs, preselected as minims with the keypad 6 key. Ctrl+down arrow to lower the second C to middle C. Esc, Esc. Selected the first note, typed shift G, shift E, ctrl E to drop the E one octave and create the chord. Selected the chord and the C with the mouse, then double-clicked the 'three between notes' icon. Result as shown in previous post, bar 4 (top) with extra stems. Selected bar. Copied and pasted. Got the usual breve plus minim erroneous tremolo.
Saved and closed the file (filename: tremolos2). Reopened it. No problem; it's unchanged. So I'm an idiot. Aha, no! Here we go. Selected all and hit the delete key. The last bar in the top stave doesn't put its whole bar rest back in the middle: it's got only two beats! I think this characterizes the bug.

Have attached the previously saved and reopened 'tremolos.mscz' from my previous post, plus tremolos2 (the one that looked OK on reopening but wasn't) and tremolos3 (after deletion of all content, with the final bar that's screwed up). See what you think.

Attachment Size
tremolos.mscz 1.71 KB
tremolos2.mscz 1.57 KB
tremolos3.mscz 1.48 KB

Yes, as I already observed, if I incorrectly try to create a tremolo by selecting the entire bar instead of by selecting the first note as you are supposed to, you do get bad results. It appears you are maybe consistently creating your tremolos incorrectly? Interesting that it seems to work sometimes, but it's definitely not how it is supposed to work. Try creating your tremolos correctly - by selecting the first note, not the whole measure - and they all work fine. Again, only copy/paste fails, and only in 1.X. It's already been fixed for 2.0, and a workaround posted for 1.X.

Meanwhile, it is probably worth submitting a separate bug report for the fact that trying to create tremolos incorrectly - with an entire measure selected rather than just the first note of every pair - doesn't fail more gracefully. Or word it as a feature request, asking that it be supported to create tremolos in this fashion in the future. Actually, your specific example does appear to work in 2.0 - entering two half notes, with the first as a chord, then selecting the whole measure, then double clicking the tremolo sign - *does* appear to work. But I don't know if that is officially supported now and will work in all cases or not.

AHA! Thank you Marc. The problem lies with the curiosity of selection in MuseScore. Re-reading the instructions on tremolos I see that I'm supposed NOT to select anything, just drag the three stripes to the first note of the pair. So yes, I'm wrong and that's the source of the problem. But since I'm allowed to shift-click to select the notes on which I want to operate for just about everything else, I'm only working intuitively and consistently within the MuseScore canvas.

I'd say selecting things in MuseScore is one of its biggest difficulties for the user, and I hope 2.0 will address some of the problems. I only learned from the web forums that you can Ctrl_click to select a set of individual notes; the manual only mentions the shift+click approach. But shift+click selects whole bars when you click on first and last notes. And why can I do a 'batch' operation like adding accents or pauses, or pitch shifts to multiple notes selected with Ctrl_click in multiple staves, but can't do the same, for eaxmple, wth cross-staff beaming?

I appreciate your getting to the root of my difficulty with tremolos. I'm more than grateful for what MuseScore offers. Because I recently had a lot of work to do with scoring, MuseScore's idiosyncrasies (let's not get started about percussion!) drove me to try the demonstration of Sibelius. I was not impressed. It simply has different idiosyncrasies. MuseScore copes brilliantly with an amazingly complex task.

Ctrl-click is a standard shortcut for multi-select in Windows, and I assume something similar is the case for MacOS and Linux. If you have other questions on selection in general, you might try asking on the forum. I find most things about selection work exactly as I'd expect, but then, I'm pretty familiar with standard Windows shortcuts, and perhaps not everyone is.

Anyhow, it's not that you aren't supposed to select anything for tremolos. They work exactly the same as most other markings, in that there are two ways they can be applied. One is to drag and drop onto a single note, and the other is to select the note or notes you wish to apply the marking to and then double click the marking. Tremolo is no different from other markings in this respect. It's just that you have to realize that tremolos are actually only applied to the *first* of each pair. So if you select the pair before double clicking the tremolo marking, MuseScore 1.X is confused and apparently thinks you are trying to create two sets of tremolo - one starting on the first note, and one starting on the second. Or something like that - obviously, it gets very confused and does something completely unreasonable. As I said, it appears this is already changed for the better in 2.0; apparently it is now smart enough to not try to apply tremolos to every note in a selection but to instead automatically divide the selection into pairs and apply the tremolos accordingly. I have no idea how smart that algorithm really is - what if the selection doesn't divide neatly into pairs? - but you might want to play around for yourself and see.