Well there is Dimmu Borgir, with an orchestra and a choir: https://www.youtube.com/watch?v=El4zsUZjsDc - and it is just nuts. Yes that's 90 minutes, but watch 5 and then decide.
I'm honestly thinking of dropping some money to get myself an A-tuned drone flute[0]. Drone flutes sound really cool, and the drone would be tuned to just about the highest two notes on the guitar... and if you work with it a bit, drums/bass/rhythm guitars helping with rhythms, chords and harmony could really push that somewhere really interesting.
And that's why I love folk-ish metal so much.
Why shouldn't we have a lead/harmony violin on top of a metal rhythm section? https://www.youtube.com/watch?v=F17sxgZdXZw
Or a hurdy gurdy? https://www.youtube.com/watch?v=LT7HqIP55tI
Or a pipa, which was btw very hilarious in poland: https://www.youtube.com/watch?v=MwpKZtPBIEQ
I'm honestly thinking of dropping some money to get myself an A-tuned drone flute[0]. Drone flutes sound really cool, and the drone would be tuned to just about the highest two notes on the guitar... and if you work with it a bit, drums/bass/rhythm guitars helping with rhythms, chords and harmony could really push that somewhere really interesting.
0: https://www.youtube.com/watch?v=j3OlNNEuu88