It is a highly complex art form that weds classical poetry and musical improvisation in specific local modes. Mugham is a modal system. Unlike Western modes, "mugham" modes are associated not only with scales but with an orally transmitted collection of melodies and melodic fragments that performers use in the course of improvisation. Mugham is a compound composition of many parts. The choice of a particular mugham and a style of performance fits a specific event. The dramatic unfolding in performance is typically associated with increasing intensity and rising pitches, and a form of poetic-musical communication between performers and initiated listeners.