I would like to contribute to add harmonica instruments. Can you indicate how this can be done.
The default soundfont already contains harmonica. You can change the sound of any instrument to this sound via the mixer. Or, create a staff for Melodica, which uses the harmonica sound already, then change the name in Staff Properties.
I guess Harmonica should be added to the instruments.xml file so it's there by default without needing to go through Staff Properties or the Mixer. You can do that yourself in your own installation by customizing your own copy of instruments.xml (in the templates folder under the installation folder) and pointing MuseScvore to it via Edit->Preferences. You could submit a feature request to the Issue tracker (see menu at right of this page) so Harmonica is added in the next release.
I would also like to add a bass, and a chord/chordet harmonica. The bass is an extension of the melodica, so a simple entry in the file instruments.xml is sufficient. However the chordet is an harmonica with 3rd and 5th harmonic. Is it possible for me to contribute to this? I assume that a soundfont need to be created?
I tried to modify the file instrument.xml but the additional entry for Harmonica-diatonic does not show in the list of available instrument to add. I am using the application in French, so I assume there is more than one file to modify?
There are several versions of the instruments.xml file, yes, be sure you modify the current one. Or, as I said, make a copy, then use Edit->Preferences to tell MuseScore to use your custom version. You may need to restart MuseScore in order for your changes to be seen.
As for the soundfont, that's trickier. The sondfont shipped with MuseScore is not developed with MuseScore; it is a third party soundfont. And since it is GM-compliant, it focuses on instruments defined by the GM standard. I don't know if there are any unused slots where you could add a new sound. So you might instead think about editing the soundfont for your own use, using one of the various soundfont editors out there to replace one of the sounds you don't use with the ones you want.
Ultimately, I'd love to see MuseScore have its own sondfont that had higher quality samples and wasn't limited to the GM sounds. That's a project I'd be interested in helping with, too, and if/when that happens, then I'm sure any sounds you have would be welcome!
We are 2 peoples that would like to add a few instrument to the soundfont and we have time at the moment to do that.
I do not mind creating a non-compliant GM file. Ultimately we could replace some of the less use instrument from the GM-compliant file and incorporate ours.
I have programming resources at my disposal where I could create an application to remove/add instrument of a soundfont, if required.
At the moment I would like to focus on creating soundfont for my harmonica sets and some percussion such as dabourka and cajon.
Can you guide me as to what process should be done, and what application to use. I think we have the proper technical knowledge to do it.
You could start from here : http://musescore.org/en/node/13734
And there are already several soundfonts for harmonica or cajun. Just google "soundfont harmonica"
I tried Viena to add hamonica bass to a soundfont, and I obtained low quality result. It is most probably because of my lack of experience dealing with the subject.
I may need a more advanced soundfont editor where processes are more automated.
How Musescore link an instrument in the file instrument.xml and a GM compatible soundfont?
By default, it's linked via the program parameter in instruments.xml. In the GM soundfont the instruments are numbered according to this program number and following the GM norm : http://en.wikipedia.org/wiki/General_MIDI#Melodic_sounds
If I take for example the Accordion. In the GM soundfont supplied with Musescore, there are 2 type of accordion defined. In GeneralUser GS MuseScore v1.44.sf2, there are 4 definition for Accordion.
How instruments.xml refer to each one?
Can I define and refer to more than one Harmonica definition in Musescore?
instruments.xml refers to only one. The one with the standard MIDI program. You can't refer to several midi programs for one instrument (except percussions, or violins/trumpet).
Regarding accordion, the General MIDI program is 22, MuseScore programs are 0 indexed, that's why you see 21.
I'm not sure what you are trying to do anyway. You know that you can change the sound of an instrument in Display -> Mixer?
What I want to do is to be able to specify different harmonica type, bass, chord, diatonic on one score. This way when played back we should hear the appropriate instrument sound.
Then first you need a soundfont with these sounds. Do you have one? Then it's just a matter of adding these instruments to your instruments.xml and the right program number.
Let's say I want to use the soundfont GeneralUser GS MuseScore v1.44.sf2, which already define 128 instruments. Is it possible to add instrument 129 for a specific instrument in both the soundfont file and instrument.xml? In other words, is it possible to go beyond the 128 instruments already define by the GM standard?
Yes and no :)
MIDI is a 7 bit system, using the 8th bit for a parity check.
This means that the maximum possible number addressable by a 1byte chunk such as a Program Change event is 127, which gives the possibility of 128 Program changes (0-127)
The Roland GS and Yamaha XG extensions use Bank Select messages which are sent in 2 bytes to extend the range of instruments available.
I don't know whether MuseScore recognises Bank Select messages, but this is the way forward if you wish to produce a Soundfont with more than 128 sounds