The Test:
A friend of mine at a gig (accidentally) dropped his electronic music pad thingy on the concrete floor...it did not work afterwards.
I took one of my music binders, and (purposely) dropped it on the floor right next to where his fell...it worked afterwards.
Winner? Music binder.

My friend did not appreciate the contest at all. He said the floor under my music binder was likely made of softer concrete.

I let him look over my shoulder and read my book for the rest of the gig.
Sometimes the old ways are better.

Ian