As a pianist, it is the bigger challenge for us , we can't choose our instrument during performance. I have been performing around different places for 8 months, retirement villages, schools, community halls, etc... Most pianos I have no problem with, but there was couple of times, there was Kawai upright piano, somehow the key is too slippy, and the action is too sticky. I have to play Mozart Sonata K330. It was a nightmare. My fingers just couldn't move or lift up quick enough. Another time, I attended my piano teacher mini concert, she has a K.Kawai grand piano, again the keys are too slippy and the action is heavy. I have to play Beethoven Pathetique. The tremolo was out balance, and I couldn't keep the left soft enough to bring out the melodies.
I feel it is not very fair during the exam, most students have to test on the grand piano which they never try it before. How often, ordinary students will have a grand piano at home to practice on. I know in the piano exam, high level students can try out the grand piano before the exam, but for short period time, how will you get used to the piano. At once time, one of my friend went for her diploma exam, there was K. kawai grand piano in the small room. She played the Moonlight Sonata. the sound of the piano is far too loud in the small room. She's so used to practice with all tone colour with her interpretion but in the small room , ff , sfz sounded that far too loud, the pp sounded not soft enough. The examiner commented her too over exaggerated, overreacted with the tone, the dynamic too bustled touch. She just got passed the exam, but in normal circumstance in the concert hall, she will be great. Honestly, not only the piano can affect the performance, the height of the seat, the position of the piano, the touch, the pedal, the tone, the atmosphere of the place, the noise, etc....