not sure if you are counting Walter Pardon as a 'revivalist'

Ooh no, not at all!

I suppose if you were 'in the tradition' modal material would not sound exotic or unusual.

I was talking about the folk revival there. If we accept Roud and Bishop's assessment of the relatively low proportion of modal tunes in the traditional repertoire, then even to a traditional singer such tunes might have seemed 'in a class of their own'. However, one current theory is that traditional singers didn't distinguish between the different modes at all - it is certainly true that some would apparently slip from one mode to another within a single song. This seems counter-intuitive to my (revivalist) ears, but who knows? I wasn't party to Walter Pardon's personal thoughts on the matter, but as a highly intelligent man and an instrumentalist, perhaps he thought about the issue more than most.

I could say lots more about melodeons, but I've caused enough thread drift already!