[realcopacetic]

@manfeed @jurialmunkey - I had this conversation with @DaveBlake a while ago - https://forum.kodi.tv/showthread.php?tid=371118

Genres in the music database are collected from the genre tag of the music files. Clicking on a genre on the genres node then shows you he artists with albums with songs with that genre. It means that "genre" in Kodi is inplicitly song genre.

It is possible via NFO files to give artists and albums a genre string, this is just text which Kodi will show on the info dialog, but it is not used for navigation or filtering.

From memory, what I did was use MusicBrainz Picard to update all of my artist/album genres to match the musicbrainz database, then I think if you use Universal Artist/Album scraper, you can choose to scrape genres using MusicBrainz. That way what's in the MP3 tags, which Kodi uses for xsp filtering, will match what's in the genre fields for Artists/Albums, so you can make an xsp rule that genre = $INFO[ListItem.Genre] and should get good matching in most cases without needing a bunch of manual updating of genres.

This is how I fill my widget for similar artists based on the select artists' genre and the results are as I would expect from memory of my collection. Before I figured this out I had the same problem that the matching was all over the place and as an interim I found I got pretty good results by doing the xsp filtering using artist bio contains ListItem.Genre. But if you're happy to update your mp3 tags using MusicBrainz database as the source, you can get it working pretty well.