For songs which have more than two singers or more (lot of musics have more than one singer), it would be interesting to add a new field called 'artist 2' for example and the possibility to add a third one if there is more singers.

Actually, the library is badly organized because I have a lot of "X featuring Y" or "X / Y" in the artist list. This proposition implies that the song will appear in the both singers' songs list.

Thanks for your attention.