I was on the subway waiting for my train, when I heard it: the tune. A few notes from a violin, soft and sad. I looked around. No one else seemed to notice. The man next to me scrolled on his phone. The woman with the stroller checked her watch. The train came to her stop, and as she stepped off, the crowds around her took no notice of the sound. She alone heard it.

It was everywhere. I’d be making coffee and hear it drift through the kitchen. I’d be in a meeting, and it would drown out my boss’s voice. I asked my friend Mark about it. He just shrugged. “I don’t hear anything,” he said. “Are you sure you’re okay?”

I started to wonder if I was losing my mind.

I searched for the tune everywhere. I played old records. I watched videos online. I hummed fragments to anyone who would listen. No one recognized it. The melody stayed in my head like a splinter digging below her skin. The more I tried to ignore it, the louder it became.

Then came again, on Sunday. I was at my parents’ house, cleaning out my old closet. My hands found a dusty shoebox hidden behind some winter coats. The tune swelled in my ears, almost frantic now. I opened the lid. Inside was a small porcelain music box. A ballerina, chipped and faded. I remembered it suddenly. My grandmother gave it to me the day before she died. I was four years old.

I wound the tiny key. The ballerina spun. The music box played the same sad, tiny notes that I had been hearing all week. I wasn’t crazy. I was just remembering, all while I was sitting alone in the closet. The tune had been inside me all my life, tucked away like the music box itself. It was my grandmother’s lullaby, waiting to be heard again. I sat on the dusty floor and let it play until the last note faded away.