I want to know the answer to the following question:
An example of improvisation in an opera is Beverly Sills variation of what movement of Handel's Giulio Cesare?
All the background I'm provided with is that "An example is Beverly Sills' complex, albeit pre-written, variation of Da tempeste il legno infranto from Händel's Giulio Cesare.". Is that enough to answer the question?
Answer: yes