COPENHAGEN, Denmark — Elvis Costello will take the stage in Copenhagen this weekend for the premiere of his opera The Secret Arias, which is based on Danish fairy tale writer Hans Christian Andersen's impossible romance with a Swedish soprano. The opera tells of a three-way drama between Andersen, Jenny Lind — dubbed the "Swedish Nightingale" — and her American impresario, Phineas Taylor Barnum, who brought Lind to New York for her first American concert tour in 1850. Costello will play both Andersen and Barnum, while Swedish soprano Gisela Stille will sing Lind's part. Costello said his work was a traditional...