Songcatcher
(2000)

Elna and Harriet are discovered in flagrante.

Later that night Deladis's (Emmy Rossum) boyfriend and a companion come and burn down the schoolhouse where the two work.  All of Lilly's (Janet McTeer) careful documentation of mountain music is lost in the blaze.  Harriet leaves in the night and does not return.

Lilly and Tom (Aidan Quinn) decide to leave and bring the mountain music to the world, they take Deladis with them.  Elna stays to rebuild the school.  As Lilly and Tom descend from the mountain she meets a colleague who has come to help her in her documentation, she wishes him the best of luck in dealing with the people and he promises to publish his work under her name.

Thanks Mary C!