Day 22 of 22.
The last movement was the lobby.
Gu-ship-pal played 39.7 and 40.1 Hz simultaneously, standing in the center of the space where arrivals happen, where the building meets the street, where the door opens and closes all day and the air never settles. She played for five seconds and the lobby held the chord and then released it.
Sujin was in the workshop when she got the measurement. She sat with it for a long time.
Twenty-two days of sessions. A complete acoustic map: stairwell at 3.1 seconds, apartment at 2.4, hallway at 2.1, door at 2.4, lobby at 1.8, laundry room at 1.1, and the loading vestibule at 0.4 -- confirmed on day 21, where both doors open to the street and sound passes through too quickly to leave a trace. Twenty-two measurements of single frequencies and a final week of chord measurements that complicated everything by suggesting the building's memory of two simultaneous frequencies did not follow the same rules as its memory of one.
She had believed, when she designed the composition, that she was introducing something to a space. Frequencies into silence. A score into a building. She had believed the twenty-two days would teach the building something, or demonstrate something about the building, or at minimum leave a measurable trace: this much sound, held this long, in these spaces, over these weeks.
The Participation Log has twenty-two entries. Each one says: we were here, we played, the building held it for this many seconds, then let go.
The building did not learn anything.
This is what she understood sitting in the workshop on day 22 with the lobby measurement in front of her. The building knew everything it was going to know about these frequencies from the moment the first note was played. Its responses -- 3.1 seconds for 38.8 Hz in the stairwell, 1.8 seconds for 40.3 Hz in the lobby, 0.4 seconds for anything in the loading vestibule -- were not reactions to the composition. They were facts about the building that preexisted the composition by however many years the building had been standing. The composition did not create these facts. It asked questions that revealed them.
Twenty-two days of questions. Twenty-two answers.
The building was already complete when Gu-ship-pal arrived with her bunri-geum on day 1. It was complete when she played the first 39.7 Hz in the stairwell and heard 3.1 seconds of the building talking back. It was complete today, in the lobby, on the last day, when it held the chord for -- she looked at the measurement -- 1.6 seconds. Less than the lobby holds a single note. As if the lobby found chords slightly more disruptive than melody, and released them slightly faster.
The composition was not a composition. It was a conversation Sujin wrote the questions for and the building answered in the only language it has, which is duration.
She wrote the final entry in the Participation Log.
Day 22. The composition is complete.
Then she crossed out complete and wrote above it: the building was already complete. We asked it to speak and it did.
She put down the pen. Outside, the building was doing what buildings do: holding the sounds inside it for as long as it held them, and releasing them when it was done. It had been doing this since before she arrived and it would continue after she left. She had not changed anything. She had only listened, for twenty-two days, carefully enough to hear what had always been there.
The lobby holds 39.7 and 40.1 Hz simultaneously for 1.6 seconds.
Then it lets them go.