This video first plays the entire piece "Ce jour de l'an" by Guillaume Dufay (1397-1474), while a short overview of mensural notation is given, including the dots of division. Then, for each voice are offered two versions: one Play Along (all voices are sounding, including the part you're reading) and one Minus One (the voice of the part you're reading has been left out, so you're on your own)! You can go directly to the chapter mark of your choice! This time you will have to figure out the most obvious musica ficta by listening (accidentals).