I don't go to concerts often but when I do, I tend to bring foam earplugs: partly to protect my hearing, partly because otherwise the music is usually subjectively painfully loud. Sometimes when I haven't brought them I make do with tissue.
Problem is, even without earplugs I always find it pretty hard to actually experience the music, comprehend the lyrics, etc. at concerts because it's so loud and distorted. Earplugs reduce the loudness (not as much as I'd like), but they also muffle high frequencies, making it even harder. I've sometimes resorted to the somewhat silly approach of having one ear plugged and one unplugged, alternating every few minutes, so I can hear the music better, while still somewhat reducing the volume accumulating over time. Probably not the best idea.
I haven't tried fancy musician's earplugs yet. I know they're supposed to provide a more even attenuation curve, but they also have less noise reduction overall, which isn't great. I suppose I should buy a pair and see what they feel like at a concert…
But do you have any advice? What's your impression of sound quality at concerts when you wear plugs?