A versatile musician, diplomat and courtier, Cavalieri served Cardinal Ferdinando de' Medici in Rome, accompanying him to Florence when he became Grand Duke. He played an important part in the celebrations of the Grand Duke's marriage to Christine of Lorraine and in later diplomatic activity between Florence and Rome, returning to the latter after what he regarded as the failure, through interference, of the celebration for the wedding of Maria de Medici and Henri IV of France.

Vocal Music

Cavalieri is chiefly remembered for his Rappresentatione di Anima e di Corpo (Representation of Soul and Body), reputed to be the earliest surviving stage-work set to music throughout. This morality was written for the Oratorians and was seen by leading figures in the Church when it was staged at the Oratorio del Crocifisso in Rome in 1600. Other claimants to have been the first to revive what was regarded as the ancient style of reciting in music include Peri and Caccini, with both of whom Cavalieri had worked in Florence.