Blue Danube waltz, op.314 The Blue Danube waltz, op.314 The blue Danube-waltz, op.314 Blue Danube waltz, op The Blue danube Waltz op.314 The Blue Danube Waltz, Op.314 The Blue Danube Waltz,op.314 The Blue Danube Waltz, Op.314; The Blue Danube Waltz,Op.314 The Blue Danube-Waltz op.314