Long an object of fascination, the Knights Templar left behind few documents related to the musical activities of their Order. Nevertheless, with the drive of a keen archaeologist, Marcel Pérès and his Ensemble Organum were able to reconstruct the oldest of the sources: a rare manuscript dating from the middle of the twelfth century and originating at the basilica of the Holy Sepulchre in Jerusalem, the site at which the rituals of the Knights Templar and the Knights Hospitaller initially took shape.