Starlight Over Pemberley
This is Pride and Prejudice fan fiction, with an introduction of a new character. An acidental time-traveler from the twenty-first century, who meets Georgiana Darcy. He is a down on his luck piano tuner and unpublished composer. He plays his music for Georgiana, and she is so moved by it, that she convinces him to sell it to her.
He instead gives it to her, but unwittingly gives her his soul.