When learning other languages, songs are a good way to help. It's good
for developing vocabulary, grammar, sentence structures, learning to
speak poetically, and it makes learning the language fun. You might find that language courses commonly use traditional songs
to help teach the language. It would be better if you know what the
lyrics mean first, so you can get a feeling of the song.

For "dead" languages, I think it's nice to sing those songs to keep
the memory of them alive. It can also be a way to bring those languages
back into common use, if you're trying to do so. I've heard tell of
languages becoming dead and re-emerging.