In the city of Bellavento, where the tram bells chimed blue notes in the morning and bakery shutters rattled awake at dawn, there lived a young sound collector named Sora.

Sora did not collect stamps or shells or shiny buttons, though she liked all those things very much. She collected sounds.

She kept them in tiny glass jars with silver lids.

Of course, the sounds did not really fit inside the jars. Sounds were too wiggly for that. A sneeze might bounce three times against the glass. A puppy bark might try to chew the label. A puddle splish could be quite damp if you were not careful.

So Sora used a special recorder her grandfather had made for her from a little microphone, an old clock spring, and a copper funnel. When she pointed it at a sound and pressed the round green button, the sound slipped inside as neatly as a firefly into a lantern.

Then Sora labeled the jar.

“Morning tram bell, Market Street.”

“Three pigeons arguing over a bread crust.”

“Rain tapping on Mrs. Okada’s umbrella.”

“Papa laughing while he sneezes.”

She had hundreds of jars on shelves in her bedroom. Some glowed softly at night. Some made tiny noises in their dreams.

Sora’s favorite sound was the one she had collected at the riverside: the soft flup-flup-flup of a family of ducks landing on water. Whenever she could not sleep, she opened that jar a crack, and the ducks would flutter across the room in a whispery little puddle-sound.

Every Saturday, Sora went out with her recorder and her yellow notebook.

She traveled through the city on foot, by tram, and sometimes on the back rack of her aunt’s bicycle. She listened under bridges, behind flower shops, beside fountains, outside theaters, and near the deep stone tunnels where the subway sighed like a giant resting underground.

Bellavento was full of sounds that most people never noticed.

There was the tiny click of a ladybug opening its red wings.

There was the tick-tick-tick of a traffic light changing from red to green.

There was the sleepy groan of the old library door.

There was the scrape of a broom across the steps of the museum just before sunrise.

One evening, as the sky turned the color of peach jam, Sora sat at her desk and listened to all the sounds she had collected that day.

The market sellers calling, “Fresh pears!”

A trumpet player practicing three wrong notes and one beautiful one.

A cat drinking from a rain gutter.

The clink of spoons in the Moon Bowl Café.

But when Sora turned off her lamp and closed her eyes, she noticed something strange.

Between the sound of the tram bell and the sound of the fountain, there was an empty place.

It was not silence exactly.

It felt more like a missing tooth in a smile.

Sora sat up in bed.

She listened again.

Tram bell.

Empty place.

Fountain.

“What are you?” she whispered.

The empty place did not answer.

The next morning, Sora carried her recorder through Bellavento, listening harder than she had ever listened before.

She visited the big clock tower.

Tick.

Tock.

Creak.

The clock tower had many sounds, but none of them fit the empty place.

She visited the train station, where suitcases rolled, shoes hurried, and announcements echoed from high speakers.

“Platform four, train arriving.”

Still no.

She went to the fish market, where ice crackled and gulls shouted as if they owned every fish in the city.

Not there.

She stood near the fire station, where the red doors folded open with a grand rumble.

Not there either.

By afternoon, Sora’s yellow notebook was full of scribbles.

Loud sounds.

Soft sounds.

Funny sounds.

Sounds that smelled like cinnamon or wet stone or warm dust.

But the missing sound remained missing.

At last, she sat on the steps of Mr. Farid’s watch repair shop. Mr. Farid was old and round and had eyebrows like two sleepy gray caterpillars. He knew the names of every clock in the city.

“Mr. Farid,” Sora said, “have you ever heard a sound that was gone, but not gone?”

Mr. Farid looked up from the tiny watch in his hand.

“Ah,” he said. “A missing sound.”

“Yes.”

He nodded slowly. “Cities have those sometimes.”

“Why?”

“Because a city remembers more than people think. A street may remember horse hooves long after the horses are gone. A doorway may remember a baby’s first laugh. A square may remember music after the musicians have packed their instruments.”

Sora leaned closer.

“Where would I find a missing sound?”

Mr. Farid’s eyes twinkled behind his round glasses.

“Listen for the quietest clue,” he said.

That was not much of an answer, but Sora thanked him anyway.

On her way home, she took a street she had never walked down before.

It was narrow and curved behind the old post office. Tall buildings stood on both sides, with laundry flapping between them like bright flags. At the very end was a blue gate covered in curling vines.

Sora almost passed it.

Then she heard something.

Not a sound.

The almost-sound of something that wanted to be heard.

She stopped.

The blue gate had a rusty sign hanging crookedly from one corner.

SUNFLOWER PLAYGROUND, it said.

But the playground behind it looked nothing like the cheerful places Sora knew.

The gate was locked.

Beyond it, tall grass grew through the cracks in the pavement. A crooked slide stood under a chestnut tree. Its paint had faded from red to a dusty pink. The swings hung still, their chains brown with rust. A merry-go-round leaned to one side, tangled in ivy.

No children played there.

No grown-ups sat on benches.

No ball bounced.

No skipping rope slapped against the ground.

Sora held up her recorder.

The little green button seemed to glow in her hand.

She pressed it.

At first, it recorded the wind rubbing through the grass.

Then the flutter of a sparrow.

Then a dry leaf scratching across the ground.

But beneath those sounds, deep and faint and trembling, was something else.

A squeak.

A faraway squeak.

Sora froze.

The swing closest to the gate moved.

Just a little.

Forward.

Back.

Squeeeak.

Forward.

Back.

Squeeeak.

But there was no breeze strong enough to move it.

Sora listened so closely that her ears began to tingle.

Then she heard more.

A soft thump, as if small shoes had landed in sand.

A bright burst of laughter.

The hollow clonk of a ball against the old slide.

A child singing, “Higher, higher, touch the moon!”

The sounds came and went like bubbles rising through water.

Sora knew at once.

This was the missing sound.

Not one sound, really.

It was the sound of play.

The sound of children discovering how high they could swing, how fast they could run, how loudly they could laugh when nobody said, “Shhh.”

But why was it hidden here?

Sora looked through the blue gate. On a bench beneath the chestnut tree sat a small wooden box. It was painted yellow, though the paint had chipped away in many places.

On the lid was a picture of a sunflower.

And beneath it, in faded letters, were the words:

FOR THE ONE WHO LISTENS.

Sora’s heart gave a tiny jump.

The gate was locked, but beside it was a low stone wall. It was mossy and bumpy, with plenty of safe footholds. Sora placed her recorder in her pocket, climbed carefully over, and landed in the tall grass with a soft whoomph.

Inside the playground, everything felt different.

The city noises became far away.

Even the trams seemed to ring more softly.

Sora walked past the slide and the still merry-go-round. She reached the bench and lifted the yellow box.

It was light as a loaf of bread.

Inside, she found a folded piece of paper and a little silver key.

The paper had been written in purple ink.

Dear Listener,

If you have found this box, then you have heard the playground remembering.

This place was once full of children. We climbed, tumbled, shouted, invented games, traded marbles, and made up songs for the pigeons.

Then the playground closed while the city planned to fix it. But the fixing never came.

The laughter stayed behind.

It has been waiting for someone to hear it.

If you wish to wake the playground, begin with one small sound.

Sora read the note twice.

Then she looked at the silver key.

At the far end of the playground, half hidden by ivy, stood a little shed.

Its door had a tiny lock.

Sora walked to it, brushing grass seeds from her socks. She slipped the key into the lock.

Click.

The door opened.

Inside was a wonderful jumble of old things.

A basket of skipping ropes.

A red rubber ball.

A box of chalk in blue, green, orange, and gold.

A tambourine with three jingles missing.

A tin whistle.

A sack of marbles.

And, resting on a shelf, a shiny metal bell.

Sora picked up the bell.

It felt cool in her hand.

“One small sound,” she whispered.

She rang it.

Ting!

The sound flew into the playground like a bright silver bird.

For a moment, nothing happened.

Then the nearest swing creaked.

Squeeeak.

The merry-go-round gave a careful little turn.

Clunk.

A forgotten seesaw rose an inch and dropped again.

Thump.

Sora rang the bell once more.

Ting!

The old playground seemed to wake up all at once.

The slide made a long, happy shhhhhh.

The swings began to sway.

The chestnut leaves clapped together overhead.

From the corners of the playground came giggles, footsteps, clapping hands, and the patter-patter-patter of a game of chase.

Sora pressed the green button on her recorder.

The sound rushed in.

It was enormous, warm, and sparkling.

It had sun in it.

It had dust in it.

It had scraped knees and shared cookies and secrets whispered under the slide.

Sora could hear children from many years ago, children she had never met.

“Push me!”

“Wait for me!”

“Look how fast I can go!”

“I found a ladybug!”

“I’m the captain!”

“No, you’re the dragon!”

Sora laughed, though her eyes felt a little watery.

Then, from outside the blue gate, came a voice.

“Sora?”

It was her friend Niko, who lived two streets away and always wore one sock with stars and one sock with stripes.

He stood outside the gate with his grandmother.

“What are you doing in there?” he called.

“Listening!” Sora called back. “Come hear!”

Niko’s grandmother looked at the rusty gate, then at the overgrown grass, then at the playground that was no longer quite so still.

The swings were moving.

The chestnut leaves were dancing.

The old slide gleamed rosy red in the evening light.

The grandmother smiled.

“I used to play here,” she said quietly. “I had forgotten.”

The next day, Niko’s grandmother told the neighborhood. Mr. Farid came with his toolbox. Sora’s aunt came with paint brushes. The baker brought sweet rolls. The people from the flower shop brought pots of yellow sunflowers.

Soon, many hands were working.

They pulled weeds.

They oiled the swing chains.

They painted the gate blue again.

They fixed the crooked slide and straightened the merry-go-round.

Sora recorded every sound.

Brushes swishing paint.

Hammers tapping nails.

People laughing as they found old chalk drawings beneath the dust.

Children gasping when they saw the playground opening again.

At the end of the week, the blue gate stood wide open.

The sign had been repainted.

SUNFLOWER PLAYGROUND.

On the first bright morning after it opened, children poured inside.

Some came shyly, holding their grown-ups’ hands.

Some raced straight for the swings.

Some sat on the merry-go-round and spun until their hair flew everywhere.

Niko tried the slide three times before breakfast.

Sora sat beneath the chestnut tree with her recorder in her lap.

She did not need to press the button right away.

First, she simply listened.

The playground was no longer remembering alone.

It was making new sounds.

New squeaks.

New thumps.

New songs.

New laughter.

And as the afternoon sun made golden patches on the ground, Sora understood something important.

A missing sound was not always lost forever.

Sometimes it was only waiting behind a quiet gate.

Sometimes it was waiting for someone patient enough to stop, listen, and ring a little bell.

That night, Sora placed a new jar on the middle shelf in her bedroom.

Its label read:

Sunflower Playground, Awake Again.

Before she fell asleep, she opened it just a crack.

Out floated the gentle creak of swings, the soft rumble of a merry-go-round, and one clear, happy laugh that skipped across her pillow like a tiny bright star.

Sora smiled into the dark.

Far away, beneath the moon, the city of Bellavento hummed and clicked and sighed.

And hidden among all its busy sounds was the most wonderful one of all.

Children playing.