I have a 2-1/2 pound book with three full CDs of music of the Cathars (Albigensians) which cost me deep in the purse. I probably have even more stuff in the 1600 CD collection of (mainly) Medieval and Renaissance music I have acquired. We will probably do it again in the not too distant future.

Most people have no idea that the First Crusade was not against Islam, but against the Gnostic "heresy" of Southern France, wiping out the most sophisticated culture in Europe at the time, a culture that established the foundation of European musi