Update: This in from the presenter who I described in the original post:

"We presented David Bromberg last night. Before introducing him, I announced that our concert series was now a "No Glow Zone": No taping, no photos, no texting, no glowing devices of any kind. I waited for either catcalls or stunned silence. Instead, the audience applauded loudly. There was nary a glowing screen the entire evening. Several audience members privately thanked me. Nice."

Looks like it worked.

Deb