Hello Hans and Mogens,
Mogens, the MIDI channel assignments in the MusicXML export come straight from the Finale file, which is as it should be.
Hans, I was able to look into this some more. There is a difference between Mac and Windows due to differences in the way the MusicXML export is handling Finale's MIDI Device Annotations across platforms. These files are external to the Finale score file, so that makes a bit more sense as to why the exports are different across platforms.
I see this file was originally created in Finale 2003 on Windows and last saved in Finale 2014c on Windows. This gives to mind a couple of best practices for MusicXML export:
- For best results, export to MusicXML on the platform where the file was created. This is especially important for pre-Finale 2012 files that use non-Roman scripts. Finale did not support Unicode prior to Finale 2012, and reading in files cross-platform could cause problems with Eastern European and other Windows or Mac scripts.
- In general results will be better with files created with newer versions of Finale. Files created with older versions have to go through more conversion steps when read in with the latest version of Finale, and are also prone to use older music entry techniques that are more difficult to export to MusicXML.
I'm not saying that these are directly related to this issue. Percussion export is complicated and I still have not found the real root cause of the problem, just one factor in why things are working differently between Mac and Windows.