Six or Seven Celtic nations?

[Ruanaidh]

I've always heard spoke of the "Seven Nations":
- Ireland
- Scotland
- Wales
- Cornwall
- Isle of Man
- Brittany (France)
- Galicia (Spain)
Gaelic (in either of its two branches) is spoken in six of the nations. Unfortunately Galicia no longer has the old tongue. The music in all seven nations is remarkably similar, sharing many instruments and musical forms.

I remember someone saying there were 6 Celtic nations, but also hearing there were 7.

So who many and which ones are included?

-Scotland
-Ireland
-Wales
-Brittany

Rest?

France? Gael-Celts
Spain? Iberian-Celts