Messiaen - Vingt Lecons d'Harmonie

These lessons are intended for students who have already completed the "apprentissage" of the Traite' d'harmonie. Their difficulty is more or less that of the harmony competitions of the Paris Conservatoire. In order to encourage the student to read the works of the ancient and modern masters, to find in them the source of the rules that are imposed on him and the licences that are tolerated, they have been conceived in the style of some of the leading authors of the "harmonic history" of music, from Monteverdi to Ravel. They are not pastiches, but a study of four voices in different styles. Some lessons are inspired by two authors at the same time. In my realisations I have always figured the bass: this figure will suffice, in many cases, to indicate the normal analysis. For the difficult passages of analysis, I will give detailed explanations below, to which I will add some advice to the students on the harmonisation of each particular lesson.
Contrary to the usual practice of publishing a pupil's book (with only the given texts) and a teacher's book (with the author's realisations), I present here a book of realisations which should be used by one pupil, guided by the teacher. The pupil will therefore proceed, for each lesson, in the following way: he will copy the bass part (if it is a "given bass") or the soprano part (if it is a "given song"), carefully hiding the other parts, and, having read what concerns him in my "remarks", he will perform, always trying to extract from the imposed melody the "natural and true" one that it assumes. Then he will read my realisation and the explanations I give. Then he will perform again, with my cipher and my soprano for the "Given basses", and with my ciphered bass for the "Given songs". Finally, he will compare this last work and my realisation.