Harmony in the Renaissance era

In Renaissance music, harmony is often created through the superimposition of several melodies. This way of using multiple voices is called polyphony. The scales used to create these melodies are known as modes, slightly different from the major and minor tonality that became established later. Because this music is based on modes, we sometimes hear harmonies that sound strange or unexpected. At this time, there were strict rules determining which notes could sound at the same time in music; wrong combinations of notes were impure and hence the work of the Devil.