Media types, UTIs, etc. for MusicXML 3.1

I wanted to let everyone know that we have a pull request for proposed changes to the last outstanding issues for MusicXML 3.1:

- The recommended media types are changing to application/musicxml+zip and application/musicxml+xml, subject to IANA approval

- There are new macOS / iOS Uniform Type Identifiers org.w3c.music-notation.musicxml and org.w3c.music-notation.musicxml.uncompressed

- There is a new recommended mimetype file to be the first entry in a zip file. This is an uncompressed text file with the text application/musicxml+zip.

- The file extension .musicxml is now recommended for uncompressed MusicXML files. Applications should also expect to be able to handle older files with a .xml extension. The .mxl extension for compressed MusicXML files remains unchanged.

This pull request is available on GitHub at https://github.com/w3c/musicxml/pull/206 <https://github.com/w3c/musicxml/pull/206>. Since the issues are so interrelated it seemed best to address them all at once. The plan is to merge this later this week. Please comment on the pull request at GitHub if there are things that you would like to see changed.

Once this is merged, MusicXML 3.1 will be feature-complete and ready for testing. We will have one remaining issue regarding converting the finale MusicXML 3.1 release to the W3C Community Final Specification Agreement (FSA). We might also pull in some addition documentation issues, and naturally will want to fix problems that are found during the beta test period.

Thank you all for your help in the development of MusicXML 3.1 over the past year!

Best regards,

Michael Good
VP of MusicXML Technologies
MakeMusic, Inc.