The Piano That Plays Itself

“Hey, have you heard? The music-room piano plays by itself.” The morning classroom hums with the rumor. One lone note, they say, in the empty room after school — and what happens to the ones who hear it, everyone will only whisper. The choir contest is three days away, and the choir is too scared to practise. Timid Momo sets a notebook on your desk with trembling hands. “You. It's time for the verification notebook.”

The verification notebook is the treasure you and Momo share: every scary rumor you've ever checked, written down. “Hey! This one's BIG.” Ren bursts in — afraid of nothing, dependable, and far, far too quick to decide. “It's wind. It's obviously wind.” Momo shakes her head. “No deciding yet. First we find the people who actually heard it.”

You find three people who heard it. The custodian: “On my lock-up rounds, by the corridor windows — a single note.” A brass-band senior: “While we packed up. It almost overlapped the sunset chime.” A library monitor: “I was returning books, passing the window side… just after five, I think.” Three voices go into the notebook. They sound scattered — and yet, somewhere, they line up.

Momo opens the school map and copies out the three testimonies. The custodian: on the five-o'clock rounds. The senior: around the sunset chime. The library kid: just after five. — The times line up. Then the places: all three heard it on the WINDOW side — the side that faces the back lane. Momo looks up. “The rumor has conditions. And if it has conditions — it has a true face.”

Ten to five. With the custodian standing by, you enter the sunset music room. Rows of music stands; the grand piano with its lid propped open. The circle of Momo's flashlight trembles on the floor. “Wind! Shut the windows and it's solved!” Ren charges at the window — “Wait.” Momo's voice is small but very clear. “If we change things before the verification, we'll never know what worked.” So first: touch nothing, and wait for the moment.

Just past five. The sunset chime fades in the distance — and then it happens. The window glass shivers with a rattling buzz, and in the same breath the piano sounds: a soft, whole-body WAH. Nobody touching it. Momo drops into a crouch — and points a trembling finger out the window. Down the back lane behind the school, a big market truck is rumbling slowly past. The window shivered. The piano sang. In the very same instant.

Into the notebook goes what you know. When a heavy truck passes, the ground trembles — just barely. That trembling travels: ground to floor, floor to the piano's legs. And a piano string is a wire stretched tight; if the trembling reaches it, it sings without being touched. It's the same thing that makes windows rattle when a truck goes by. …Probably. Now — how do you turn “probably” into “it was”?

The market truck takes the back lane once a day, on weekday evenings. The contest is in two days — there aren't many chances left to test. “We change one thing at a time — right?” Momo grips the walkie-talkie at the safety line in the corridor and whispers, “You, run the verification. …And please hurry.” What to test, and how — that's yours to decide.

Three tests sit in the notebook: the windows, the corridor door, and the space under the piano's legs. Change one at a time and watch the moment the truck passes. When every test is done — point at the true face.