Nigerian theatre makes extensive use of music. Often, this is simply traditional music used in a theatrical production without adaptation. However, there are also distinct styles of music used in Nigerian opera. Here, music is used to convey an impression of the dramatic action to the audience. Music is also used in literary drama, although its musical accompaniment is more sparingly used than in opera; again, music communicates the mood or tone of events to the audience. An example is John Pepper Clark's "The Ozidi Saga", a play about murder and revenge, featuring both human and non-human actors. Each character in the play is associated with a personal theme song, which accompanies battles in which the character is involved.