Bright colours, new hopes, and endless horizons. If you could set the American Dream to music, it’d probably sound very like Aaron Copland’s Appalachian Spring – the 1944 frontier ballet that took the old hymn ‘Tis The Gift to Be Simple and sent it out into the world. It’s the calm, strong centre to John Wilson’s exploration of American music in the 20th century – a concert that ranges from the jazz age sheen of Barber’s comedy overture to Leonard Bernstein’s deliciously sophisticated take on Plato, in the form of a violin concerto. And to finish, a leading candidate for the title of the definitive Great American Symphony: Roy Harris’s taut, muscular Third.