There are composers who are known for a single opera, and there are operas that are known for only a single aria. But to be a 19th-century Italian opera composer and to be remembered solely for your ballet music – well, that’s a bit special. As the orchestra tiptoed into the ‘Dance of the Hours’, in Act Three of Grange Park Opera’s production of Amilcare Ponchielli’s La Gioconda, the audience sighed with recognition.