That book has an ending I keep replaying in my head. The final chapters escalate the tension between Lena and the Keeper of the Valley, shifting from a magical conflict to a raw confrontation about grief. Lena finally understands the melody wasn't a curse on the town, but a containment field for the Keeper's own sorrow, which had leaked out and poisoned everything.
Her choice isn't to destroy the melody, but to join her voice to it, harmonizing in a way that transforms its nature. It's a resolution that's heavy on emotional logic over magical rules, which some readers found unsatisfying, but it landed for me. The final image is of the odd melody becoming part of the town's normal soundscape, a bittersweet hum in the wind rather than a terrifying force, with Lena left standing alone in the now-quiet valley, forever changed by the act of understanding rather than conquering.