Elvis Costello is composing an opera based on Danish fairy tale writer Hans Christian Andersen's unrequited love.
Costello was nominated for an Oscar for his Cold Mountain song
The Secret Arias will feature 19th Century songs written by Andersen for Swedish soprano Jenny Lind, who never returned his affection.
"Elvis immediately loved the idea," said Henrik Engelbrecht, head of drama at the Copenhagen's Royal Theatre, where the opera will be staged in 2006.
Andersen's stories included The Little Match Girl and The Ugly Duckling.
Lind was known as the Swedish Nightingale and it is believed Anderson wrote his tale The Nightingale with her in mind.
Andersen was Denmark's national poet and this year marks the bicentennial of his birth. He died in 1875.
Costello emerged from the UK's new wave scene in 1977, scoring 16 hit singles including Oliver's Army and I Can't Stand Up For Falling Down.
Since then he has dabbled in everything from orchestral symphonies to harmonious pop, teaming up with musicians including Sir Paul McCartney and Burt Bacharach.
Last year he was nominated for an Oscar for the song Scarlet Tide, co-written with T-Bone Burnett, from the film Cold Mountain.