Music to prick the conscience. In the wake of their American historical oratorio Sanctuary Road, inspired by William Still’s sprawling chronicle The Underground Railroad, the Pulitzer Prize-winning composer Paul Moravec and his amanuensis Mark Campbell turn to an equally fraught chapter of our history. A Nation of Others takes us to Ellis Island in 1921, which just so happens to have been the year of the racist Emergency Quota Act, precision-tooled to lock the door against immigration. —M.G.