Och, guest you miss my point! It is that notation can not express the Gaelic lilt that makes Irish and Cape Breton music so full of life. As I stated above notation has been used for learning tunes but not for playing them. The Fraser, collection, as you state, is well known here and Skinner and the Gows are regarded as Gods. There have also been great composers on this side of the pond such as Dan R MacDonald, Gordon MacQuarrie, and Dan Hughie MacEachern, whose music has returned to Scotland.
David Greenberg is a classically trained violin player who has put, without doubt, a great deal of effort in learning to play fiddle in the Gaelic style of Cape Breton. I have heard him perform a few times and I think that he does this very well. I am sure that he could have easily played the same tunes from sheet music, without any effort , but he comprehends that it just would not be the same.
It is not the tunes themselves, that was lost in Scotland and survived in Cape Breton, but the style of playing them. The thread was discussing the influence of Gaelic on the music of Scotland and Ireland and here that can still be found. Many think that is because the old dance, stepdance in particular, required this playing style, and they are most likely correct.