Piano in High School Music Room

Listen to this story... please hear it till the end. This happened during my senior year of high school in winter. The college entrance exam was over and I was staying at school until 9 PM almost every day preparing for university applications. That's when it happened. One Friday night in December 2020. I was studying in the library and came out to use the bathroom... when I faintly heard piano music from the 3rd floor. It sounded like a Chopin nocturne. But it was strangely slow and kept stopping and starting. "Is someone still practicing?" I thought, so I went up to the 3rd floor music room. But it was strange. All the music room lights were off. Only the emergency lights in the corridor were dimly lit. As I got closer to the door, I could clearly hear the piano. Nocturne No. 9 in E-flat major, 2nd movement. I knew because I used to learn piano. But the performance was somehow awkward. Hesitant like a beginner, repeating the same parts over and over. I peeked through the small window next to the door... and then... It really gave me chills. The music room was completely dark. But in that darkness, only the piano keys were visible in white. And those keys... were moving by themselves. As if invisible fingers were pressing them. What was even scarier was the piano bench. Nobody was sitting on it, but the chair was slightly tilted back. As if someone was sitting there leaning against the backrest. The performance continued. But it always stopped at the 2 minute 30 second mark. Then started over from the beginning. The same pattern repeated three times. I was too scared and tried to run away, but suddenly the performance stopped. Then the piano lid slowly closed down. Nobody touched it. The next day I carefully told the music teacher. At first she didn't believe me. But when I said "It kept stopping at 2 minutes 30 seconds in Nocturne No. 9, 2nd movement," the teacher's face went pale. "No way... that can't be..." The teacher told me about Kim Su-jin, a senior who graduated 10 years ago. That senior was supposed to perform Nocturne No. 9, 2nd movement at the graduation recital, but she died in a car accident a week before the performance. "Su-jin practiced that piece so hard... but she kept making mistakes at the 2 minute 30 second part and never completed it to the end. Not even once." Hearing those words gave me even more chills. Even after death, the senior was still trying to complete that piece. I heard it several more times after that. Always Friday nights around 9 PM, always stopping at the same point. One day I tried to be brave and open the music room door... but the handle was freezing cold. It shouldn't have been that cold indoors, even in December. On the last night before graduation... I heard that piano sound again as expected. But that day was different. It went past the 2 minute 30 second mark and played to the very end. Perfectly, beautifully. After the performance ended... it became really quiet. And I've never heard that sound again since then. Did Kim Su-jin finally complete her performance? Or is she still somewhere practicing that piece? And... is someone still listening to her performance even now?