Beethoven’s quartet smiles, Schumann’s recalls past masters, and Bartók’s mourns. Beethoven’s string quartet is a genial work that’s especially witty in its quicksilver finale. Schumann revered Bach and Beethoven, evidenced in his String Quartet No. 1, with its involved counterpoint and gravitas juxtaposed with its quicksilver, daredevil finale. There is little peace in Bartók’s String Quartet No. 2, a stark work that reflects the composer’s inner turmoil in response to the horrors of World War I.