John Kirkpatrick, on his midwinter album "Wassail", does a set of 'three terrific old dance tunes that were given new English words during the nineteenth century' {quote}. The first is 'The Nantgarw Flower Dance' which was 'traditionally done in Wales on New Year's Eve, and is also known as "Nos Galan", which means "New Year's Eve" in the Welsh language.' {quote again}

Does that make anything clearer?

Nos dda!