[Geoff Bacon]

I don't know if this will cover all your points but it sounds as though you should be using collections (a song can be in more than one collection).
e.g. have a Jazz collection, a Country collection

When importing a song. add it to one or more collections (the song will have the same name in each collection). You can edit a song to add it to another collection if you forget to add them when importing.

I have a different scenario in that I am in two Uke groups which share a lot of songs. My solution is to keep separate versions of the songs for each collection (one per group) so that they can diverge if necessary.

So, I guess you need to mix and match these two methods to achieve what you want to do.


Geoff
PS: To edit an existing song, long press on it's name on a library screen (until the tick appears) and then select edit on top line

PPS For Lyricist, you could use a Custom field (never used them myself)