This dream is a strange combination of two different periods in my life: high school and grad school.
I dreamed that I had gone back to my high school to attend some kind of alumni function. I went into the dormitory where I'd lived in high school only to find that it had been extensively renovated. This renovation involved restoring it to its original ornate decor (very different from real life, I assure you), and, as a special touch, the heavy, carved oak doors had been elaborately inscribed with the names of the original occupants.
I found my room, which was upstairs, second door from the stairs. The names on the door were lovely, but I didn't recognize them. They were something like A. D. Smith and Mabel Something.
I wandered around the dorm, at one point going into the basement looking for the "trash room." I found it, and realized that the basement had certainly not been renovated, and the trash room was overflowing with garbage.
Later, I attended a performance of some kind. Someone I knew from my grad school days (here's the mashup) was in this show, playing a piece on piano (as far as I know she doesn't play at all). In the dream, I knew this piece, having played it myself. I knew that it was very difficult, with an elaborate accompaniment pattern played in the middle register with the thumbs and forefingers, and the melody played with the right pinky finger. It required lots of delicate touch and jumping around on the keyboard, both of which require absolute control.
I was really impressed with her performance, and during the applause, I went backstage to congratulate her. I found her stretched out on the floor (apparently exhausted by the effort of performance). She was surrounded by family members, her two babies, and a couple of small dogs. As they all swirled around her, I knelt by her head to gush about her playing. I kissed her on the forehead and told her she'd done a wonderful job, and that I totally understood how hard it had been.
(Upon waking and considering the piano piece, I know that whatever she was playing wasn't what my dream self thought it was.)