The only music was that which came from behind the curtain at the rear.
Further directions for the performance of a madrigal drama by Vecchi tell us that when a single person speaks on the stage, all the musical parts join in representing him.

In the case of a dialogue between two actors the voices are to be divided into two groups situated so that the musical sounds shall seem to proceed from the actors.

For example, when Lucio and Isabella converse, men's voices represent the former and women's voices the latter.

The subjoined passage of dialogue between Frulla and Isabella, Act II, scene fifth, will show how two voices were represented: [Musical Notation] In the "Fidi Amanti" of Torelli there is a scene for two men, a satyr and a shepherd, and one woman, a nymph.

In this the two men are represented always by the tenor and the bass, the latter having the chief burden of the delineation of the satyr.