The question is not whether the Asturians, or anyone else, are Celts (although serious doubt has been cast as to whether the so called Celtic tribes actually constituted a distinct ethnic entity).

The question is whether the indigenous musics of the Celtic regions are sufficiently similar to each other, while at the same time being sufficiently different from all the other the other European ethnic groups, for "Celtic" music to be safely regarded as a distinct entity. I don't think they are. In fact I think that the musics of the Celtic regions are as much a part of the musical melting pot of Europe as any other European race or ethnic group, or social culture.