What's wrong about listening to metal?
I both play the whistle, and my six guitars - and I love both folk and metal, and mixing those two simply gives an amazing result, mostly. If you take a look at the scandinavian metal-scene in the mid-90's, a trend began to unfold - what metal-folks today usually refer to "melodeath", og melodic death metal - back then, there were to types of that musical style: One focused on the folk-melodies of scandinavia and tremolo-picking, the other style was more thrashlike, riff-wise - a band like Dark Tranquillity and In Flames are good examples of exactly that.
About a year ago, I stumbled across a faroese band called Týr. They mix inspirations such as Dream Theater (who many refer to as the kings progressive metal) and their musical heritage - and the result is amazing. The lead singer sings in faroese, danish and english - apart from the traditional folk-songs they have modernised, they have also made a cover of The Wild Rover - which actually ended up sounding quite nordic, for some reason.
To make a long story short - folk metal rules!
..and I still keep thinking of bands.
Ashtar, is a brazilian metal-outfit, focussing on the irish and celtic musical heritage - some of their songs are simple modern remakes of traditional songs, and some are more metalesque - some even with doom metal-like vocals - quite interesting, when exploring that kind of music.
#Wormdiet
Opeth is an amazing band - one of the best progressive death metal-bands that ever shot out of Sweden - and about those vocals, Mikael Åkerfeldt is an amazing vocalist - his clean vocals are beautiful and fragile, while his growl is meaty and clear, yet still extremely distorted - you don't see that kind of talent a lot, what death metal-vocalists concern.