In 1928 Berg started work on his second and last opera: "Lulu". He had thought about the opera for many years. He had seen a play called "Die Büchse des Pandora" "(Pandora’s Box)" in 1905. Wedekind had played the part of Jack the Ripper. People thought the play was obscene, but it still became very popular, especially after 1918 when there was no more censorship in Germany. He worked on the opera until 1934. He then stopped work on it to write his "Violin Concerto". When he heard about the sad death from poliomyelitis of a young girl he knew called Manon Gropius, he dedicated the concerto to her memory. He wrote: “To the memory of an angel”. Manon’s mother, Alma, had been the wife of Gustav Mahler.