What is Orangum known for in the context of medieval music?

Orangum is recognized for its contribution to the development of polyphony in medieval music, particularly the practice of adding a second voice to plainchant. This innovation marked a significant evolution in musical texture, moving from monophonic music, which is characterized by a single melodic line, to the more complex structure of polyphony where multiple independent melodies interact. This foundational change in music laid the groundwork for further developments in Western music, including the rich harmonies that would emerge in later centuries. By introducing a second voice, Orangum not only expanded the sonic possibilities of medieval music but also influenced the compositional techniques that followed, making it a crucial aspect of the musical landscape of that era.