There are no Celtic people left, only derivative cultures. Breton, Cornish and Welsh, Irish, Manx, Highland and possibly Galician.
One of the common used terms that particularly irritates me is “celtic music”. When used, it most often refers to Scots/Irish and Canadian Cape Breton.
This is not Celtic music, but the music of separate cultures that descended from the people others called Celts.
In addition to Irish and Highland Scottish, there are derivative cultures
• Breton music (the biniou and bagad bands) is starting to be heard more widely on this side of the Atlantic.
• Welsh singing but is renown, but how many of us know the sound of their traditional instruments (crwth, pibgorn, tabor).
• Cornish music (Cornish double pipe, Crowdy Crawn) can be heard mostly in local festivals.
• Manx music (the lur and harp) are also are in revival, but their sounds are also rarely heard outside local festivals and fairs.
• Galicia & Asturias in northern Spain near (or even over) the Portugese border are often included in the list although there is some question over how much of the Celtic culture remains.
I play the Highland bagpipe and its music. The pipe music is varied (modern, dance music, marches through to piobaireachd). I do not play Celtic music.
I recently heard someone who was talking about various music style and listed Scots-Irish, Celtic and Cape Breton. I doubt that by Celtic, she meant Cornish, Manx, Welsh or even Beton.
So why Celtic music? Probably a mix of lack of knowledge and laziness.
If it’s Irish music, it’s Irish music, etc. or the blend that is now called Scots-Irish. It’s not Celtic. We should be more specific.