[Steinway]

...and another thought - though probably quite far-fetched.. A couple of pages before the black page appeared, I noticed the page suddenly resize itself slightly even though I was nowhere near with my fingers. I then realized my headphone cable was touching the screen, and wondered if there could be any kind of intereference from this cable which made the tablet believe I was trying to pinch zoom. Is there any chance this could be related to the black pages that appear? I certainly haven't used headphones every time I've seen the black page, but I realize I may have done so quite often - either connected to the tablet (listening to associated audio files) or connected to the piano while practicing. At other times, when the black page have appeared without me using headphones, there may have been a humidity control system on the grand piano which may have caused some kind of intereference with the tablet. Of course, I'm not even sure this is possible or in any way could explain what I'm seeing, I'm just clutching at straws, desperate to find an explanation...