(unfinished work by @wooka)
Lo Boier is an old chant by the cathars - one of the few things left of them
many crusades were not against muslims, but in fact also against other catholics and also cathars
very nice version
and cool to see these singers also sing "these songs" :)
probably would not have been possible while the inquisition, nor a little later..
and with the internet, there now also is an audience which makes it worth to also sing these kind of songs
in german (but unsure how accurate the translation..):
not the best information about it, but also not bad
good introduction