Flags points in wrong direction in compound meters

• Dec 30, 2014 - 16:50
Type
Functional
Severity
S4 - Minor
Status
closed
Project
MuseScore

In beam groups in compound meters combining long and short values, the flag of the first short note value in the beam group points to the right. However, it should actually point to the left, as the subsequent flags in the beam group do.

Steps to reproduce bug, expected behavior, and actual behavior:
Enter notes in compound meter in a "dotted rhythm" connected by a beam group. The flag of the first short note value in the beam group should point to the left, but instead points to the right.

In effect, the latter part of beam groups in compound meters are being beamed as though they are in a duple, not triple meter.

I am attaching a MuseScore file that illustrates this behavior in various contexts.

Running MuseScore v1.3, Revision 5702 under OS 10.9.5.

Thank you -- MuseScore is a great project and I really appreciate all of your work on it!

Attachment Size
Compound Meter Flags Example.mscz 2.35 KB

Comments

• Dec 31, 2014 - 07:17

Actually, I would argue that measures 2 & 4 are correct according to my interpretation of Elaine Gould's "Behind Bars". Each beams unit shows represents a group of three sixteenths, and the rule should be, the partial beam for a note that starts on the second of the three must point in the direction of that beat.

However, I would agree that measures 1 & 3 are wrong. Here, the beam could actually have been broken between the first and second groups of three sixteenths, so the partial beam that would have been part of the first group should point in the direction of that group.

See also #40806: Sub-beam in wrong direction. Might be nice to solve both of these together.

Reply

• Jan 13, 2015 - 22:08

Thanks for your reply! Would it be possible to make this user-configurable? In compound meters it would be helpful to have the flags show the dotted rhythm, rather than pointing away from the group. (For example, see Beethoven's piano sonata Op. 111, the L'istesso tempo section of the Arietta movement in 6/16 time.) I'm working on a piece now with the same dotted 16th note rhythm as the Beethoven, and the flags (excerpted in my example) indicate a syncopated duple rhythm rather than a dotted rhythm.

As always, I really appreciate all the work everyone's done on MuseScoree and the site....

Reply

• Mar 4, 2015 - 15:41

I looked at this. The algorithm for determining the direction of the partial beam is pretty simplistic right now, although it works in a lot of cases. It mkes no attempt to "understand" the beaming for the time signature, so it doens't get that 3/16 is different from 4/4 in this respect.

I am guessing that code was written before the current scheme of having beaming defaults in the time signature properties was implemented. Probably we could use that info to do better. I will investigate this.

Reply

• Mar 4, 2015 - 17:18

I have a fix I am testing. It will use the beam groups from time signature properties to decide on this, so indeed, it will be configurable. Measures 1 & 3 in the example above would be fixed by setting 16ths to beam in groups of threes (which you should be doing anyhow in 6/16); measures 2 & 4 would be fixed by settings 32nds tobeam in groups of threes (which to me is not really standard, but seems to be consistent with what you want here).

Reply