Question: What type of performances of Baroque ear Operas require improvisation?
Sentence: Improvisation is also an important aspect in authentic performances of operas of Baroque era and of bel canto (especially operas of Vincenzo Bellini), and is best exemplified by the da capo aria, a form by which famous singers typically perform variations of the thematic matter of the aria in the recapitulation section ('B section' / the 'da capo' part).
Answer in sentence: yes