Comment 4 for bug 1823515

@Owen Williams: It would be really nice if tracks with identical albums were inserted in reverse track-number order, rather than alphabetical. Reverse because this would allow sorting by newest-first date-added to also sort albums in the correct order.

Alphabetical is not necessarily useful, because even well named tracks are sometimes named e.g. `artist - album 1 track.mp3`, and this means that tracks 10-19 get inserted before track 2.

I would insert all files found at the same time alphabetically by:
- artist, then
- album, then
- reverse disc number, then
- reverse integer track number.
And fallback on alphabetical by filename if none of those exist.