Characteistics
Organum
Organum is a plainchant melody with one added voice to enhance the harmony. It was originally improvised. A Bourdon or bass line may also be sung at the same time. It involved two musical voices; a Gregorian chant melody & the same melody transposed by a constant interval (usually a perfect 4th or 5th). Over time, composers began to write added parts that were not just simple transpositions, thus creating true polphony.
Polyphony
Polyphony formed from Organum. In music, polyphony is a texture consisting of two or more simultaneous lines of independent melody. Polyphony was generally either "pitch-against-pitch" / "point-against-point" or "sustained-pitch" in one part with melismas of varying lengths. This point-against-point conception is opposed to "successive composition", where voices were written in an order with each new voice fitting into the whole.
Organum is a plainchant melody with one added voice to enhance the harmony. It was originally improvised. A Bourdon or bass line may also be sung at the same time. It involved two musical voices; a Gregorian chant melody & the same melody transposed by a constant interval (usually a perfect 4th or 5th). Over time, composers began to write added parts that were not just simple transpositions, thus creating true polphony.
Polyphony
Polyphony formed from Organum. In music, polyphony is a texture consisting of two or more simultaneous lines of independent melody. Polyphony was generally either "pitch-against-pitch" / "point-against-point" or "sustained-pitch" in one part with melismas of varying lengths. This point-against-point conception is opposed to "successive composition", where voices were written in an order with each new voice fitting into the whole.