I don't know about any folk events, but I've spent quite a bit of time in that lovely part of S Wales over the years. One of my favourite places there is Rhosili, at the SW corner of the peninsula. There's a gorgeous unspoilt sandy beach there and at low tide you can walk across to the island of Worms Head - but beware! Make sure you check the tide tables and allow plenty of time to get back before the tide comes back in. I nearly got stranded there once and just managed back in time. And the sunsets there are spectacular too!

Have a great time.