I use the foamies, various brands such as North, EAR, etc. that are OSHA mandated in noisy industrial environments. Probably not fantastic for concerts as I'm sure the frequency response curve sucks. They sure as hell block noise though. I hate sticking them in my ears, as I've never found such things comfortable, although I can tolerate them for 3 or 4 hours. Supposed to be around -30db.
Fantastic at race tracks. I normally use sealed 'phones with my scanner, -30db, but sometimes at local races I don't use the scanner, so I use the foamies. I generally carry about 10 pair and pass them out to people around me. We can carry on conversations fairly well and not be listening to the cars 2 days later. Probably the same as Rite-Aid, but I grab a habdful every time I'm in a plant some where.
Most live music I hear these days is jazz trio's and quartet's, and they really aren't that loud.