Who were not staged or costumed but were performed with the performers A chorus was added?

In various theatrical productions, particularly in classical or modern adaptations, the term "chorus" often refers to a group of performers who provide commentary, context, or emotional depth to the narrative without being fully integrated into the main action. These chorus members typically do not wear elaborate costumes or engage in staged choreography but rather serve as a collective voice that enhances the audience's understanding of the story. Their presence can evoke a range of emotions and insights, enriching the overall performance.