Ahh! Highland Cathedral - that well known modern German work, which many a Scots piper has claimed as Trad. 'old Scots' That is the subject matter theme that makes it Scottish, not the nationality of the writer. Deliberate faux nationality.

Probably thousands of examples of that... Johnny Cash - 'Forty Shades of Green' etc.   - song subject matter makes it Irish.

More confusing is the likes of 'Wild Mountain Thyme' adapted in modern times, by the Irish and then re-acquired by the Scots.   

As I said before on the crazy example here an album called 'My Irish Roots' - song 'Highland Road' performer Dundee's 'Denis Clancy'. Scottish song, Scottish writer, Scottish Performer - Irish record company eejit (not intended as any slur on the Irish themselves). How Irish is this?
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"...Then I'll march along to a Scottish song on the road that's wild and free, though the lonely glens by the Highland Bens - it's the Highland Road for me" author/composer Stewart Ross