Polyphony is used to create more expressive sounds. A voice playing a melody by itself is not as expressive as two independent voices playing different melodies simultaneously. Polyphony makes music more complex and enjoyable since it requires more than one listen to really appreciate it. Every listen could be very different from each other. For instance, one can listen to a certain voice as the main voice in one listen and choose another voice as the main voice in another. With a multitude of different themes playing at once, one can create many different combinations when listening for patterns.