In the lower gallery of the Great Burl, beside the warm steam of the central water tank, lay the Acoustic Forum—a circular tiered arena where the elders of the clan gathered to deliberate, teach, and record the communal history of the twelve roots.
Here, the floor was composed of twelve massive blocks of stone-hard bitter pine-resin wood, each three arm-lengths square and five inches thick, arranged in a perfect circle around a central sounding pit. Each block had been planed to a specific thickness and sound thickness, so that when struck by a wooden mallet or a bare heel, it produced a precise, unchanging musical pitch ranging from eighty hertz up to four thousand hertz.
Qiao Ming and Yan Zhiqiu sat upon woven rush mats on the northern arc of the circle. Across from them sat Clan-Mother Zhen, Elder Xiu, and four master scribes of the clan, each holding a pair of polished boxwood tapping rods eight inches long. The air was warm, lightly fragranced with bitter pine-resin oil and steam.
Beside Yan Zhiqiu, the Broken Slate was propped against a low wooden frame stand. Her soapstone pencil was poised above the dark stone, ready to record the deepest principles of the underground language that had baffled surface scholars for three thousand years.
