What is an oratorio?

An oratorio is defined as a large musical composition for orchestra, choir, and soloists that typically tells a religious story, performed without the use of staging, costumes, or acting, which distinguishes it from opera. The essence of an oratorio lies in its emphasis on the musical illustration of sacred themes through narrative and choral passages. Notable examples include Handel's "Messiah," which presents biblical texts through rich musical settings.

In contrast to the other options, a comedic musical play implies performance elements like staging and costumes, which are not features of an oratorio. A secular concert with dialogue suggests a less formal structure and often does not focus on sacred themes, deviating from the traditional purpose of an oratorio. While a dramatic choral arrangement can be a component of various musical forms, it does not encompass the broader context of a narrative arc or thematic development that marks an oratorio.