"An Wasserflüssen Babylon" is a paraphrase of Psalm 137, which reflects on the emotions of the exiled Jewish people in Babylonia. “By the waters of Babylon, we sat down and wept when we remembered you, o Zion. As for our harps, we hung them up upon the poplars.” Here, Assistant Director of Music Mark McDonald plays Bach’s setting of this beautiful chorale on a practice organ in his living room. The organ's digital samples come from the 1713 Boizard organ in France's St-Michel en Thierache Abbey. Listen to the plaintive sound he uses for the left-hand melody – it is meant to evoke the human voice.