This particular form of organum was called parallel organum, which consisted of a cantus firmus in the bottom voice, and an added voice that moved in parallel 4ths or 5ths with the cantus firmus. In the 10th century, a newer form of organum emerged known as free organum. In free organum, the cantus firmus is still in the bottom voice, however, the added voice moves in a note-against-note manner rhythmically in a variety of intervals. In the 11th century, there is an increasing popularity in the idea of rhythmic independence, which brings music into a period of melismatic/ florid organum. The cantus firmus remains in the bottom voice, with the added voice having melismatic sequences moving over the sustained notes in the cantus
This particular form of organum was called parallel organum, which consisted of a cantus firmus in the bottom voice, and an added voice that moved in parallel 4ths or 5ths with the cantus firmus. In the 10th century, a newer form of organum emerged known as free organum. In free organum, the cantus firmus is still in the bottom voice, however, the added voice moves in a note-against-note manner rhythmically in a variety of intervals. In the 11th century, there is an increasing popularity in the idea of rhythmic independence, which brings music into a period of melismatic/ florid organum. The cantus firmus remains in the bottom voice, with the added voice having melismatic sequences moving over the sustained notes in the cantus