Multiple genres per album/track

[divanikus]

Hi. I know there is no standart against tagging with multiple genres, but this feature looks very promising in terms of managing library and creating playlists. Think of it as of tags (hashtags) for your music. One album could be tagged as say Folk Rock and Rock. So if you want to listen some Rock, it would be there, if you want to listen just Folk Rock - it would be there too.

Many tagging software do support having multiple values for Genre field, at least for id3v2.3+ tags. It might be proper multivalue field or just a string with separator, usually ";" or "/" (Folk Rock;Rock, Doom Metal/Metal). Some players and library organizers do recognize multiple values and they really put albums and tracks into multiple genres. I can say for sure, that Volumio does support it, Kodi does support it, MusicBee (for Windows) does support it.

Currently owntone-server does not support multiple genres, they are all seen as long strings with ";" separator in the UI. It would be really cool to have this feature too!

[hacketiwack]

This enhancement is related to #886.