Course on Medieval Notation.

[Machaut1377]

Some members of this forum might be interested in this:
https://www.futurelearn.com/courses/from-ink-to-sound

It is a four week course and the material for the fourth week is already up, but the (free)course is available for another few weeks, I believe, and you can work at your own pace. I am taking it and I find it pretty interesting.