Kannel/Kantele
It is a very traditional instrument, used in at least Finland and maybe some other countries have copied it as well. It would greatly fit world and lore of HnH.
Here you can see kantele in action.
In Kalevala, Väinämöinen, a great wise old man made a kantele out of pike's yaws, maybe that could be a rare thing that you could get when you fish pike.
Some music played with kantele
https://youtu.be/hFCixLn9qRw
https://youtu.be/rFpsh3-a1Mk
https://youtu.be/-xsovUi9bk4
Of course it should have 5 strings, no more, no les!
