which i will then upload and release under a free
license (which ones do you recommend in this case erik?)
Although I'm not Erik, I'd recommend you to use some of Creative
Commons licenses (CC-BY or CC-BY-SA of any versions). GFDL is not very
good for music. Also you can release it in public domain if you like
to :)
*does it have to have a text, or can it also be just
nice music?
*in case of a text, which one is preferred?
This is purely my opinion that it doesn't. Wikimedia is an
international organization, but text has to be on one language, so it
possibly would be suitable in the first time, but then you will have
to compose new songs for other languages.
— Kalan