[TBone]

Using MSP, try Songs>New [top of screen]>camera ikon on the right.  
I did a complete book of several hundred and didn't have any problems. I used my phone mounted on a tripod.
I have used "Microsoft Lens" with no problems also.
After playing with it again, it seems that is what you"re doing. Sorry, looks like I have no help to offer. When I did get poor quality, it turned out it was always the original was"bad".

I should have included that I am using the camera in my Galaxy Ultimate S10 tablet.  I will experiment with lighting and hopefully the few music sheets that have some grainy spots will disappear.  Thanks.