Not even the diehards know everybody. You can have a deep passion for New Orleans and Louisiana music, and there’s still somebody performing at the New Orleans Jazz and Heritage Festival presented by Shell that you’ve never heard of. That’s where we come in. Here’s our guide to this year’s performers and, to be fair, we had to look some of them up, too. As usual, we’ve coded the stages as follows: ACU (Acura Stage), GEN (Gentilly Stage), CON (Congo Square “My Louisiana” Stage), JAZ (WWOZ Jazz...