Orchestra Rehearsal 1978

In a Medieval Roman chapel, now an oratorio, an elderly factotum sets up for rehearsal. The musicians arrive, joking and teasing. A union shop steward explains that a TV crew is there, talking to them is optional, and there will be no extra compensation. Musicians talk about their instruments. The German conductor arrives and puts them through their paces. He yells, he insults. The shop steward calls a 20 minute break. The conductor retreats to his dressing room and talks about how the world of music has changed, moving away from respect for the conductor. He returns to the rehearsal to find the orchestra in full revolt. What can bring them back to the music?