Here are my suggestions (I am French):
- lead vocals: chant (principal ?)
- tag: tag
- artist name: nom d’artiste
-
legal name: vrai nom
Pity that old forum is dead and not recovered yet.
What I said in MusicBrainz en français (internationalisation / Transifex) could have been of some interest, it contained suggestions for some other terms, IIRC, but it is not archived.
I am completely not comfortable in Transifex, I have unsubscribed from there, it felt totally obscure and insecure to me. Anyone can overwrite anything once and for all, or so it seemed.
But alors, mais you are French, @Yvanz!? 