[TJ]

I was just listening to Ramund Hin Unge and I was just woundring if there are any particular guitar scales that Trad. music goes by?

any ones knows??

[Séafra]

Yeah, I could tell you a couple basic things about the tonality of Nordic folk music. First of all guitar is not found in the very old folk songs generally, but of course nowadays you can play whatever you want. The closest thing to guitar would have been dulcimer-like instruments.
There are differences in every region, but usually the tunes are in a minor key, but many are major. Some songs were unclassifiable as major or minor, but then when the accordion became popular the tonality became more fixed. You asked about scales, just practice your regular major and minor (all 3 forms of minor) in various keys. The tonality isn't much different from other styles of music. some strange intervals and things, but the scales are usually just harmonic or natural minor.
Some examples of some tunes you might know:
Torsteins Kvaedi- Harmonic Minor
Hårgalåten- Harmonic Minor
Varmlandsvisan- Natural Minor
Herr Mannelig- Natural Minor

[Heri Joensen]

Torsteins Kvæði combines harmonic and natural minor.

Ramund hin unge is in natural minor and harmonic minor as well. The verses are in natural minor and the chorus is in harmonic minor.
Thoug I think it has a dorian feel to it, if the sixth note were in the scale (it is not) it would probably be a large sixth, which would make it dorian. Many of the Faeroese ballads are in dorian. It is a slightly major'ized form of minor, and it has a very medieval feel to it. Ólavur Riddararós and Regin smiður are both pure dorian. The notes in the other voices in the chourus that fall outside dorian I have added myself.
_________________
Deyr fé
deyja frændur
deyr sjálfur ið sama
Eg veit einn
að aldrei deyr
dómur um dauðan hvern

[Séafra]