oratorio Look up oratorio at Dictionary.com
"long musical composition, usually with a text based on Scripture," 1727 (in Eng. 1644 in native form oratory), from It. oratorio (late 16c.), from Church L. oratorium (see oratory (2)), in ref. to musical services in the church of the Oratory of St. Philip Neri in Rome, where old mystery plays were adapted to religious services.