Rappresentatione di Anima, et di Corpo

Emilio de' Cavalieri regarded himself as the composer of the first opera or oratorio, with the Rappresentatione di anima et di corpo, (libretto by Agostino Manni). Whether or not he was actually the first is subject to some academic debate, as is whether the work is better categorized as an opera or an oratorio.

Source

 * Rappresentatione di Anima, et di Corpo