Even in a festival anchored around a handful of 20th-century composers touched by the presence of war – Benjamin Britten, Dmitri Shostakovich, Béla Bartók, Witold Lutosławski – the program on Thursday night with the Rundfunk-Sinfonieorchester Berlin and their chief conductor, Marek Janowski, was especially haunted by the memory of atrocity. It was a night of tough music with little reprieve.