Leoš Janáček’s two string quartets are a deeply moving revelation of the heart-rending emotional turmoil that marked the composer’s final years. The Britten Quartet’s spirited and passionate interpretation does wonderful justice to these neglected masterpieces, paired here with two chamber music pieces (the Violin Sonata and Pohádka, in which the ensemble’s musicians Andrew Shulman and Peter Manning are accompanied on the piano by Ian Brown)