There couldn't be jigs if reels exist either, and where protest singers fit in?

Why by country M'Unlearned friend?

Actually, some might take it further than by country and point to regional styles.

Jigs and reels exist in the traditional repertoires of several countries but can be played in national/ regional styles. One might for example be able to hear whether the same reel was played in a Scottish or Irish style.

I'm not sure that protest singers really fit in with this as there does seem to me to be a sort of universal protest song style.