Anyone serious about music nowadays wouldn't bother with paper.  A full computer monitor is a lot more economical than an ipad & easier to read.  There's a 4k monitor for $180.

 https://www.amazon.com/Sceptre-3840x2160-DisplayPort-Speakers-Metallic/dp/B073X6G4DZ/

Just whack a raspberry pi on it.  The minimum resolution for a page of music is around 1600 vertical.  There are many used monitors in the 1600 pixel range for $50, or the 1920 pixel range for $60.  Stand one on its side & the deed is done.  

There are 2 surviving 15" laptops from years ago.  A 17" one which contained one of the very 1st 64 bit opterons is gone. If the electronics are rearranged, they might become displays.

Reading a single page at a time is not ideal, but the lion kingdom has gotten by with an ipad.  There will always be the memory of viewing 4 printed pages at a time.

The trick is a stand for it.  Even better would be a music notation program for it & a way to draw annotations.