Just as an add-on to Kathy Wallis' message re: the Mari Llwyd (et al.) singing in Wales. It's generically referred to as Ymryson Canu (ymryson = um RUH son, challenge, contention) and (canu = CA nee, to sing) - quite common at one time in community singing and special occasions such as Christmas (above) and weddings.

Sian