In the first half of the evening, keyboardist Max Holman and string artist-in-residence Benjamin Cline share Pärt's "Spiegel im Spiegel" and Bach: Cello Suite No. 2 in D minor, Prelude and Fugue No. 15 in G major from WTC Book 2, and Viola da Gamba Sonata No. 1 in G major. In the second half, the Ad Astra String Quartet digs into the chamber music repertory in its inaugural season. They'll play Nico Muhly's 2011 composition, Diacritical Marks and close with the finale of Dvorak's American Quartet.