Haunting soundtrack

Siri is, much to my surprise, able to identify the music playing throughout this movie.

It is Give Me Strength, Mother by Garth Neustadter.

The song title is also a climatic line 'spoken' by Gish (via a title card) once her long-lost love returns and she struggles with her vows to the convent and God.

https://www.youtube.com/watch?v=AKgq7GE7Zvg