add support for playback of custom key signature

• May 18, 2010 - 01:15
Reported version
P3 - Low
S5 - Suggestion

I created a score with a custom key signature (with B flattened and C sharpened) and entered three notes: A, B(b), C(#).
It displayed correctly, as A, Bb, C#.
I played the score.
It played A, B, C, as if no key signature had been added.
I changed the key signature to F major (which also has a flattened B).
It incorrectly added a natural in front of the B, and did nothing to the C.
Again, it was acting as if there had been no key signature there previously.
I've attached a test score with the fault.
This bug occurred on version 0.9.6 RC1 (revision 3070) and also on the latest revision 3085.
I'm running windows vista.

Attachment Size
playcustomkey.mscz 1.63 KB


I'm using Mac OS version version 3400.

I'm wondering about implementation of custom key signatures in playback? Has it been implemented yet and if not, any estimates of when.

and a question about note entry with a custom key signature - Let's say your key signature had a G# only. if you are entering notes with a midi keyboard and play G#, will the note show up as a G or as a G#?


Any news about this feature ? I'm looking for the same feature. In addition, it could be really cool feature if it also plays micro-tonal custom key signature !

The custom key signatures appear to have no impact on the notes and act as if the music were still in C major: see attachment

There is no cancellation of the custom key signature and there is no effect on the notes (see first bar --- the F has to be manually transposed up)

I really hope that this will be implemented, even though it is unconventional. Particularly the cancellation of the custom key signatures, it will make music editing so much easier.

Attachment Size
customkeysignatures.png 28.02 KB
Reported version 2.1 3.0

Indeed it will not be solved in 2.X. If anyone wants to take a look, I'm happy to guide you. You can find me on the forum or on IRC #musescore on

Fix version