The BBC Symphony Orchestra, conducted by Marin Alsop, performs UK premieres of three works by American composer Philip Glass at the Barbican Hall.In an interview with presenter Charles Hazlewood, Philip Glass discusses the influence of the 9/11 terrorist attacks on his work and explains why he is uncomfortable being referred to as a minimalist composer.Music includes the European premier of Concerto Fantasy for Two Timpanists & Orchestra with solo timpanists Jonathan Haas and John Chimes.