Oratorio

An oratorio (Italian pronunciation: [oraˈtɔːrjo]) is a large musical composition for orchestra, choir, and soloists. Like most operas, an oratorio includes the use of a choir, soloists, an instrumental ensemble, various distinguishable characters, and arias. However, opera is musical theatre, while oratorio is strictly a concert piece – though oratorios are sometimes staged as operas, and operas are sometimes presented in concert form.
wikipedia: Oratorio (https://en.wikipedia.org/wiki/Oratorio)