There are many bands (such nightwish) that almost all on lirycs in English, although they are finnsh. In other hand druidi Kivimetsän sing all lirycs in finnish.
I like to understand the lyrics of the songs but at the same time I do not like groups that are not expressed in their language.
I believe that a middle, and sing some songs in english and other in their native language is a good idea.
is your point?

