Who were two most important French composers of organum and discant during the Medieval period?

The two most important French composers of organum and discant during the Medieval period were Leonin and Perotin.

Leonin:

- Worked at the Notre Dame Cathedral in Paris in the late 1100s and early 1200s.

- Known for his organum compositions, which featured two or more voices singing different melodies simultaneously.

- His famous composition is "Magnus liber organi"

- He established the concept of organum purum.

Perotin:

- Succeeded Leonin as the choirmaster at Notre Dame Cathedral.

- Further developed the techniques of organum and discant, which incorporated more complex rhythms and harmonies.

- He developed organum triplum and quadruplum forms

- His major composition "Sederunt principes".