Music interview: James MacMillan on a new work inspired by war poems, premiering at this year’s Cumnock Tryst

At the heart of this year’s Cumnock Tryst Festival, themed around the Armistice Day centenary, is a major new work by the festival’s founder and director, Sir James MacMillan. It’s an oratorio based on texts by a First Word War poet, though not a name we’d readily identify among the customary ranks of Sassoon, Owen and Gurney.