Who was in love in the plot of sonata for harp and bicycle?

In "Sonata for Harp and Bicycle" by Joan Aiken, the main characters in love are a young woman named Jane and a ghost named the Harpist. Jane, who works in an old building, is enchanted by the Harpist's music and learns about his tragic past and unfulfilled love. Their connection transcends time, illustrating themes of love, loss, and the lingering impact of past relationships. Ultimately, their bond serves as a poignant reminder of the power of love that endures beyond death.