that cathedral was begun by louis vii and i wrote a book on chartres cathedral and his wife was chartraineur video is featured there at the sculpture. this history begins right in the 1160s and the major part of the cathedral took about 100 years to be built. so this is the very time when it was that musicians were creating so much new music for that particular cathedral which was dedicated to the assumption of the virgin mary, that is august 15th. and louis vii had not been able to produce a male heir and when he did in 1165, it was philip augustus. so it was a celebration of his own heir, his male heir, the only one he could produce by this chartrine woman, that led him to wish to have this monument and to connect it to the feast of the assumption which was close to the time when his male heir was born. so much of the music is written for the virgin mary that we have studied and it was there at the cathedral of notre dame that musicians learned how to write down precise rhythms for music, for musical repertoire. so the place of this cathedral as a cradle of our musical guild is very much