I'm assuming it's [anonymous] or [traditional] instead of unknown, but which is more appropriate?
Here's more info if it helps:
I've always used [anonymous] myself.
For Gregorian chants specifically?
Yup. There is [religious music] but that's supposed to be a subset of [unknown] and I feel [anonymous] is a much more reasonable fit.
And yet the contents of [religious music] seems to be almost entirely Gregorian chant... perhaps something needs to be redefined or retagged?
In any case, I'm trying to update this stuff at the moment, but there will be other similar cases soon: https://beta.musicbrainz.org/artist/410bc3b7-b61c-4af4-b805-71beb9e02aae
No other input on this? I'm going to change them all to [anonymous] until further notice.
[anonymous] is perfectly fine when release doesn't credit any composers. It's still good to remember that composers are known for some old pieces and also new works are composed under this genre/style.
Tying into the „What is Classical“ discussion, I’d actually prefer the track artist to be the performers (choir and/or conductor) rather than any of these bracket composers.
Yes, this goes against CSG.
That's how I tag my personal collection. But for putting stuff in the database, I try to follow CSG regardless.