Final answer:
The recitative is the device typically used to connect sections of an oratorio, mimicking speech rhythms to advance the narrative between arias and choral parts.
Step-by-step explanation:
The device typically used to connect the sections of an oratorio is known as a recitative. The recitative is a style of delivery in which a singer is allowed to adopt the rhythms of ordinary speech. In the context of an oratorio, which is a large musical composition for orchestra, choir, and soloists, the recitative serves as the narrative bridge between different sections, such as arias and choral parts. This musical device allows the story of the oratorio to be told and the action to flow smoothly from one piece to another, ensuring that the audience remains engaged with the unfolding drama.