This weekend (13 and 14 July), Cymdeithas Yr Iaith Gymraeg (the Welsh Language Society) celebrates its 50th birthday with a massive festival in the historic pavilion at Pontrhydfendigaid in West Wales.
The festival features a broad swathe of Welsh-singing and thinking musical performers, from established names like Meic Stevens, Heather Jones and Gruff Rhys, through to much newer bands like Sŵnami and Creision Hud.
On this week's programme, I spoke to Gruff Rhys about the important contribution Cymdeithas Yr Iaith has made over the years in support of Welsh music.
