Comment 4 for bug 165036

Are you writing a programming language or a music player? The player should not require technical expertise to do cool & useful things with it.

You can't assume that your users' computers will be networked (am I supposed to leave my desktop computer on, and the database exposed to the internet, while I'm travelling with my laptop?), and you can't assume that they'll want to worry about what backend database they're using. Further, if they backup their music, it's a perfectly reasonable feature to backup the metadata with the music (and, fine, this can be optional if you really don't want it to be default behaviour). See digikam for a good model; it puts its database next to the photos you are managing. I don't know if it stores any metadata inside the photos or not, but when you backup your photos folder, you've also backed up the database.

There are plenty of corresponding fields to your metadata in the id3 spec, but for the missing ones consider extension fields such as id3v2.4.0 spec, field 4.2.6. You could easily condense the basic user-set information into a string, and read it back later.

If you don't want to be helpful, fine, go ahead and close the bug. But please don't mark it as invalid. The database being "hidden" so that it's not readily backupable alongside music, and being non-portable, are both constraints to the usefulness of the program.