What happened?

I moved quickly toward the door and reached for the door knob. As soon as I touched the door knob, it grabbed me from behind. My knees buckled as I dropped onto, what I assumed, it's lap. My heart pounding as I sat silently. The room filled with a roaring silence, that seemed to consume me.I was tense. I remember squeezing my eyes shut in fear of what it was going to do. Then a wave of realization washed over me like a gentle breeze on a hot day of practice. It wasn't breathing as heavily in fact it stopped breathing. I'd opened my eyes to look around. Astonished I lightly gasped as I saw a grand piano in front of the monster I sat on. Our school had no grand piano. We only had three smaller pianos and four electric ones. Each were never stored in the same room. I looked around only moving my head, as to not cause discomfort to the creature I was sitting on.