An oratorio is a musical drama that tells a story from the Bible. Mozart wrote only one oratorio, and for his subject he oddly chose the story of Judith. In the story, Judith sneaks into the camp of the Assyrians, who are to preparing to wage war on the Israelites. She gains access to the leader's tent and cuts his head off. Without their leader, the Assyrians disperse and Israel is saved. This gruesome story was ignored by Handel, Hasse and other contemporary composers more prominent than Mozart, but who was going to tell the 15-year old Mozart what was proper material for his music? The Overture is suitably dark and stormy. It is in three parts and the last section is thematically connected to the first. The middle section is sweet and melodic, yet contains the underpinnings of tempestuousness that characterize the rest of the overture and indeed the rest of the oratorio. To many, it foreshadows the masterful Requiem he would compose two decades later.