When Claudio Monteverdi arrived at the court of Mantua, he was initially engaged as a viol player. This is an aspect of his musical personality that is too often forgotten. Yet his brother Giulio Cesare reminds us in a letter that his improvisations on the viol alla bastarda were remarkable. At the time of his arrival, instrumental music played an important role at the court, which was dominated by the personalities of several musicians, chief among them the violinist Salomone Rossi.