Complex sentence: The Florentine singer Margherita Romana and Ippolita Recupita (a singer in Cardinal Montalto's service) were deemed unsatisfactory, and a third singer from Bergamo, whom Monteverdi had suggested, refused to come to Mantua.
Split into simpler sentences: The Florentine singer Margherita Romana and Ippolita Recupita (a singer in Cardinal Montalto's service) were deemed unsatisfactory. A third singer from Bergamo, whom Monteverdi had suggested, refused to come to Mantua.