When Chaucer first introduces "Sir Ulrich" in his speech, the crowd doesn't react at first because the Czech extras didn't understand it. Mark Addy's loud prompt tipped them off to start cheering. The awkward moment was left in because it made the scene funnier.
Director Brian Helgeland once said in an interview that he used modern music in the movie to show modern audiences what people then felt about their music. When true Renaissance music is used in modern movies, it fails to convey the emotional response that people back then had to such music.
Plenty of effort was expended creating lances that would splinter convincingly without taking out the stunt riders as well. The body of each lance was scored so it would break easily, and the tips were made of balsa wood. Each was also hollowed out, and the hole filled with balsa chips and uncooked linguine to make convincing splinters.