File:Imperfect consonance in Machaut.PNG

x's mark thirds and sixths. Guillaume de Machaut's "Je ne cuit pas qu'onques".

See: File:Imperfect consonance in Machaut.mid

Source

 * Marquis, G. Welton (1964). Twentieth Century Music Idioms. Englewood Cliffs, New Jersey: Prentice-Hall, Inc.

Fair use for Consonance and dissonance
The image linked here is claimed to be used under fair use as:
 * 1) it is a very short portion of one part of the entire piece;
 * 2) the transcription is only being used for informational purposes;
 * 3) it is inferior to the original piece;
 * 4) Its inclusion in the article adds significantly to the article because it shows consonance and dissonance through history.