Setting the scene inside the theater, the author describes the audience: "The youths in the gallery had taken off their coats and waistcoats and hung them over the side. They talked to each other across the theatre, and shared their oranges with the tawdry painted girls who sat by them. Some women were laughing in the pit; their voices were horribly shrill and discordant. The sound of the popping of corks came from the bar."
What does "discordant" mean?