David Lang’s The Day for solo cello and spoken voice is a string of brief human portraits plucked from the results of an internet search, each beginning with “I remember the day…” Impactful for their wit, poignancy, or simplicity, they’re beautifully intoned by Kate Valk and accompanied by a multi-layered cello line that grows ever more intense as the piece reaches its keys moments. The Day is remarkable, too, as the prequel to Lang’s World to Come, a meditation on the separation of body and spirit in response to the tragic events of 9/11. Cellist Maya Beiser is mesmerizing from start to finish.