The "Silent Sisters" cancel the Salzburg orphan boys choir performance at the annual harvest festival in the convent when a storm partially destroys the monastery. Amadeus and Nannerl plan to perform instead. Devilius, Mario and Monti turn up and put Amadeus out of action with a nasty trick so Mario can perform instead. In the end, Amadeus saves the convent from closure by forming a fantastic choir with the nuns, who break their vow of silence to sing along. The Music: "Missa brevis in C" (Sparrows' Mass) K. 257; et al. Additional Content: Monti explains how children can create their own music video on the Web site by combining and editing 10-15 scenes from the series and setting it to the series' theme song.