The music in the princeling Hyacinth’s voice still played in my mind. It was possible that the grotto was a part of this continuous dream . . . or, perhaps, it was also possible that everything was real.

* * *

By morning, Papa had already spoken to Herr Schachtner about Woferl’s newly discovered talent. Not a few months afterward, as if the princeling had sent them himself, letters began to arrive from Vienna. The royal court wanted to hear us perform.

THE ROAD TO VIENNA

We waited until the worst of winter had passed before Papa began preparations for our first trip. The cold days dragged by one after the other. Outside, the Christmas snow fell. The Bear and the Witch and the Giant roamed the Getreidegasse and children ran squealing from them in delight. Sometimes as I watched from the window, I thought I caught a glimpse of Hyacinth walking with the wild bunch, his blue eyes flashing up toward me. Then he would disappear, leaving me to think I must have imagined it all.

During those short winter days, Papa sat at the clavier with Woferl for hours, praising his swift memory and his accuracy, clapping whenever my brother finished memorizing another piece or added his own flourishes to a measure. Woferl hardly needed his instruction. One day, I came into the music room to see my brother holding Papa’s violin, his shoulder barely big enough for the instrument. He was not only teaching himself the strings, plucking each one and figuring out the correct notes as he went—but inventing a tune. He was already composing.

I’d heard my father call other musicians prodigies before, but they were men in their teens and twenties. My brother was just a child. I stood frozen in place as I watched him. His eyes stayed closed, and his fingers fluttered as if in a trance.

With me, too, our father turned more serious, extending my lessons, noting my every mistake and nodding in approval each time I played flawlessly. I savored every moment of his attention. Even when I wasn’t at the clavier, I sat with my notebook in my lap, poring over the pages in search of whatever magic Hyacinth had cast on it.

I could see no visible change in the pages, but something had changed. I could feel the tingle of it in my fingertips whenever I brushed the paper.

On a day when the spring thaw dripped from the trees, Woferl and I stood outside the arched entrance to our building and watched Sebastian and our coachman drag trunks of clothing across the cobblestones, throwing them unceremoniously into our carriage’s boot. Mama chatted with Papa as they worked. I could see her unfolding and refolding her arms in barely disguised anxiety. She did not want to leave home.

Their Majesties Emperor Francis I and Empress Maria Theresa. I kept my hands folded in my skirts and repeated their names silently. Vienna’s royal court. Mama had said that kings and queens are remembered. Perhaps being remembered by royalty was the same.

Beside me, Woferl shifted his weight from one foot to the other, trying in vain to keep his excitement subdued. His eyes were bright with anticipation this morning, and his brown ringlets brushed past flushed cheeks.

“What are we going to do for two weeks in a carriage?” he asked me.

I leaned down toward him and raised my eyebrow. “Having no clavier on the road does not mean you can get into mischief. Papa and Mama will not have it, do you hear?”

Woferl pouted, and I patted his head. “We will find something to pass the time. The countryside will look beautiful, and soon you will get your instruments back.”

“Will they have an ear for music, do you think?” he asked me curiously. “The emperor and empress?”

I smiled at his boldness. “Best not ask that question at court, Woferl.”

He tucked his hand into mine and leaned against me. I noted how much thinner and stretched out his fingers already felt. The softness of his youth was rapidly disappearing from his tiny hands. “Herr Schachtner said the emperor likes a spectacle,” he said.

And a spectacle they would get. Woferl’s improvement on the clavier only quickened with each passing week. Papa had to commission a tiny violin for him. Before Woferl, it was unheard of for a child his age to play the violin at his level. That quality of instrument simply did not exist in the shops. Our names now regularly circulated the Getreidegasse, whispers on the tongues of the curious and skeptical that Herr Leopold Mozart’s two children were in fact both musical prodigies. They would say my name first, because I had played for longer. But they saved Woferl’s name for last, because he was so young.

I tried to keep my unease at bay. I woke up early every morning of the winter to practice, staying at the clavier long after Papa had left for the day. I’d play and play until Woferl would tug on my sleeve, begging for his turn. When I was not at the clavier, I tapped my fingers against the pages of my notebook and hummed under my breath. I spent my days wrapped in the music, lost in its secrets. When I dreamed, I dreamed in new measures and keys, compositions I would never dare write down.

I was, after all, not my brother.

Sometimes, over the long winter, I’d also dream of Hyacinth whispering in my ear. Desire is your lifeblood, and talent is the flower it feeds. I’d wake and play his menuett on the clavier, the tune I’d heard in the grotto, wondering whether it would call him back again. Perhaps he was watching us right now as we stood outside our home, his pale body washed warm by the light. Out of instinct, I tilted my head up toward our windows, certain I would see his face there behind the glass.

“Nannerl.”

I looked down to see Papa approaching, and straightened to smooth my skirts. He placed one hand on Woferl’s messy head of curls. “Time to head into the carriage,” he said gently.

Woferl released me, then ran off to hug our mother’s waist, babbling affections all the while.

Papa touched my shoulder and led me over to the corner of our building, so that we stood partly in the shadow of the wall’s edge. I looked directly at him. I did not do this often; my father’s eyes were very dark and frequently shaded by furrowed brows. It was a stare that dried my throat until I could not speak.

“Nannerl,” he said, “this will be a long trip. I’ll need you to keep your wits about you and conduct yourself like a young lady. Do you understand?”

I nodded quietly.

Papa’s gaze flickered over my shoulder toward the carriage. “Woferl’s health has been delicate lately. All this winter air.” I nodded again. My father did not need to tell me. I had always known this about my brother. “Two weeks in the carriage may wear him down. Take care that he does not catch a chill. The emperor specifically requested his presence, and if we are to perform again in Europe, we will need Woferl’s reputation to precede us.” He put a hand on my shoulder. “Be mindful of your brother.”

I waited for him to tell me to take care, too, but he did not. My hands brushed at the edges of my petticoat. Specks of dirt had spoiled the fabric’s light color. “I will, Papa.”