Yes, it is funny that the most frequent language featured on the Cat besides English is Irish Gaelic. I think a large reason for this is that there are so many Irish songs in English, and performers of Irish music often include an Irish-language song or two along with a repetoire of instrumentals and English-language songs. Thus many English-speaking 'folkies' become attracted to the Irish language.

But here are some past threads that indicate Mudcatter interest in songs in other languages:

Russian folk
Hebrew, Yiddish and Ladino songs
the last teardrop Victor Jara
rembetika
Afrika
Egyptian folksongs
Algerian links
French-Canadian songs
Scandinavian sites

The above list is by no means exhaustive. Just do a forum search for 'French' and you'll find many threads on particular French language songs. Several of the threads I list here include links to sites specialising in music from particular parts of the world.
I sure hope I got all my links right!