I often consult a website called Thesaurus Musicarum Latinarum of Latin writings on music theory and practice. Note that the web address changes every couple of years.
Why "musicarum latinarum" in the first declension? Why not "musicorum latinorum"?
In the masculine, it would read "thesaurus of Latin musicians" (music theorists really), but in the feminine it appears to read "thesaurus of Latin musics", which makes no sense to me.