By eighteenth-century standards, Rosetti was a successful musician. He joined the Hofkapelle of Prince Kraft Ernst while still a young man and served the Wallerstein family for sixteen years. Beginning in livery as a servant-musician, Rosetti advanced quickly to Hofmusikus and eventually Kapellmeister. Much of the recognition that Wallerstein achieved as a center of musical excellence was the result of his leadership. In particular, commentators frequently cited Rosetti's commitment to precise performance and expressive finesse. When he left Wallerstein, Rosetti's successful record there enabled him to secure another appointment as Kapellmeister, this time to the Duke of Mecklenburg-Schwerin, whose court was also recognized for the exceptional quality of its music.

Rosetti spent his entire adult life in the service of the nobility. He served his aristocratic employers in various ways—as a servant, performer, conductor, teacher, administrator, and composer. In each of these roles, his primary duty was to please his prince. His music was composed according to the demands of his patron and fashioned after the resources at court. Fortunately, in both of his court appointments Rosetti served musically literate individuals who were receptive to his work. His own creative aspirations were restricted only by his patron's musical proclivities and taste. However, he was assured that his music would be performed, a condition essential to his artistic development. This arrangement enabled him to experiment with new ideas, to which he would receive immediate feedback. Moreover, the musicians who manned these ensembles were his friends and colleagues.