The composer and outstanding clarinettist Jörg Widmann studied with Wolfgang Rihm in the late 1990s. Since then Rihm has composed no less than 10 pieces for him. Uber die Linie II for clarinet and orchestra, which Rihm wrote in 1999, must be one of the most substantial, an exacting test of any clarinettist's control and stamina. The soloist plays almost continuously throughout the 37-minute work that the orchestra sometimes supports and accompanies, sometimes contradicts. The music is full of allusions to past styles, and its effect is fragile and haunting. Four years ago, Rihm produced his "fourth music for violin and orchestra", Coll'Arco, for Widmann's sister Carolin; it's another single-movement concerto haunted by the past, especially by Berg's Violin Concerto, and the Viennese world of bittersweet expressionism, to which Carolin Widmann responds with intensity.