I have a small suggestion here. I've found that nearly every performance I've
heard that used a PA system was too loud.

For my own protection I always carry a set of Etymotic Musician's Ear Plugs
when I attend such performances. The ER-9s are used at places with moderately
loud systems; ER-15s for most club dates and ER-25s for all rock concerts and
car audio events.

These plugs have balanced attenuation and mostly avoid problems with Foamies or
solid rubber plugs such as loss of intelligibility and the occlusal effect. Its
very similar to just turning down the volume.

They aren't cheap, it'll cost $100-120 for a set with custom ear molds and
you'll have to see an audiologist. Etymotic also sells a set (ER-20) with
tri-flange inserts for $20 that gives 12 dB of attenuation that also work quite
well.