After World War II, two significant musical organisations were founded, the Welsh National Opera and the BBC National Orchestra of Wales, both were factors in Welsh composers moving away from choral compositions to instrumental and orchestral pieces. Modern Welsh composers such as Alun Hoddinott and William Mathias produced large scale orchestrations, though both have returned to religious themes within their work. Both men would also explore Welsh culture, with Mathias setting music to the works of Dylan Thomas, while Hoddinott, along with the likes of Mervyn Burtch and David Wynne, would be influenced by the poetic and mythical past of Wales.