Midi Channel Effects
Currently, as far as I know, the only channel effects are for string instruments and trumpets. I find that sometimes I need to write a mute for trombones, too. Moreover, I sometimes need to give trumpets french horn cues with bucket mutes. I'm not suggesting you implement a midi channel for every type of mute—that would be ridiculous. I think it could be easily done with the ability to change instruments in a midi channel (Staff Text Properties). This may already be being looked at—if so, I apologize. I just thought that midi effects such as trombone mutes should at least be brought to attention.
Much thanks,
iHasCheese
Comments
You can edit the instruments.xml file (see Edit->Preferences) to add the relevant info for trombones or other instruments, using the entries you in under trumpet as a model. Then you'll be able to add mutes for trombones on the same way - altlhough few soundfonts actually inclu a muted trombone sound, so It may not get you any anywhere. I do think I saw some facilties in the nightly build to do this sort of thing more directly, but you're still at the mercy of the soundfont you are using to provide the sound.