Sentence:  Back in the days before grammar split off from grimoire, when magic was taught alongside poetry, and rhetoric was an application of philosophy, Priest/esses and bards passed along to their initiates the correspondences between their languages' particles of sound and the parts and patterns of the world around them. Tragically, as cultures were conquered by new religions and their old wisdom-keepers persecuted, most of this oral <WSD>soundlore</WSD> was lost—forcibly forgotten, or buried beneath the new priesthood's patter and Babel. 
Meaning of the word marked with <WSD> tags:  Information or knowledge about sounds.