Wrong base value used for duplet in some time signatures

• Jun 23, 2018 - 23:30
Reported version
S4 - Minor

See https://musescore.org/en/node/273438

My case is similar:

1) new score, 5/4
2) select a full measure rest
3) Ctrl+2

Result: a duplet of two quarters, which seems way too short of a note value to fill a 5/4 measure.

I get that sometimes there can be debate about what note value to use for a given tuplet. Like, in 5/4, should a full measure triplet be represented as three halves or three quarters (do we round up or down). But I can't think of any reason for a full measure duplet in 5/4 to only use quarters. The choice should be two halves or two wholes, maybe two dotted halves if you're into that sort of thing.

Oddly, Ctrl+4 yields four quarters. Odd in that we somehow end up using the same note value for a duplet as a quadruplet of the same duration. On the other hand, no corruption - the ratio reports as 2:5 and 4:5 respectively. So not a huge deal.

Bug exists in 2.1, 2.2.1, and still exists in my fairly-current build of 2.3. So it's survived the turmoil over different tuplet reduction schemes :-)


I guess MuseScore is choosing the longest note value it can that evenly divides the duration. For a duration of 5/4, the quarter note is the longest that evenly divides it. For a duration of 9/8, the eighth note is (if we discount dotted notate values). So I suppose the algorithm is successfully doing what it sets out to do. Still an open question as to whether it's the best choice.

One thing it suggests is that we should have an explicit override for tuplet numbers available. For a duplet in 5/4, I'd probably want to use Ctrl+4 to split into four quarters, then combine into two halves, which I can do - but my only choices for the number display as "4" or "4:5". I'd want to override it to say "2".