1/ attending a concert is not a civil right
2/ can't emphasize enough, but _get an ID_. While ID posession was used to discriminate against groups of people, the real problem here is "why doesn't everyone have an ID"?
What I brought up was, knowing this, is still using ID discriminatory?
Edit: Dang it, the best answers always come after I close my laptop. "It would be discriminatory if the government didn't provide people a way to get ID. As a business owner, that's beyond the scope of my responsibility. Same as if someone showed up without $5 and wanted to buy a sandwich." ...is another way to look at it.