Erm...I suppose Ensiferum has performed too, but so has others. "Karjalan Kunnailla" is a Finnish folk song, I think it's unfair to to give the honour for it to a certain group of people. Ensiferum is a metal band, and this song certainly isn't metal.It seems Valter Juva has written the Finnish lyrics.
I guess it shouldn't really matter but those who don't know the Finnish tradition will receive wrong information
The original folk tunes are called Karjalan kunnailla lehtii puu, Myrskyluodon Maija and Metsämiehen laulu.
Alkuperäiset kansansävelmät ovat nimeltään Karjalan kunnailla lehtii puu, Myrskyluodon Maija ja Metsämiehen laulu.