Porgy and Bess: Lucerne Festival finally embraces operatic diversity with this sparkling take on Gershwin

• An aura of exclusivity has hung over the Lucerne Festival ever since its foundation in 1938, allowing one of classical music’s great summer jamborees to promote the world’s top artists in something of a bubble. But the winds of change are blowing even over Lake Lucerne, and the whole of this year’s festival is being presented under the banner of “Diversity”. With typical Swiss pragmatism, the festival’s executive and artistic director Michael Haefliger said in an interview, “We don’t have to be