Two of Czech composer Janacek's greatest non-theatrical works, Sinfonietta and Glagolitic Mass, are performed by the London Symphony Chorus and the BBC Symphony Chorus and Orchestra conducted by Pierre Boulez, with vocal soloists and organist Simon Preston. There's also a rare chance to hear Janacek's Capriccio for piano and chamber ensemble, with pianist Jean-Efflam Bavouzet. Sara Mohr-Pietsch presents.