“I feel I must fight for Der Wald because I want women to turn their minds to big and difficult jobs; not just to go on hugging the shore, afraid to put out to sea.” So wrote Ethel Smyth – and if you picture the cause of music written by British women as a ship, ploughing through the treacherous waters of 20th-century sexual politics, it does indeed have Smyth as its figurehead, dressed in tweeds and holding her cigar clear of the spray. Thanks to Glyndebourne and others, her opera The Wreckers has had lots of recent attention, but Der Wald was arguably the more important work. In 1903, it became the first opera composed by a woman to be staged at the Metropolitan Opera, New York. The second – Kaija Saariaho’s L’Amour de Loin – was 113 years later.