Late 19th-century Paris opera-goers felt cheated if their evenings-out didn't include a ballet scene somewhere in the performance.
When Giuseppe Verdi was told that he had to write such a score and insert it into the drama, interrupting the action, he was apalled. When told that he had do do it if he wanted to make any money, he became more tractable.
Hence our featured work this week: the ballet suite from Il Trovatore -- just for Paris.