Long, long ago in May, 1990, OffBeat presented its “Jazz Fest Survival Guide,” commencing with these words of wisdom: “It’s true what they say—that it’s hard not to have a good time at the Jazz Fest.” Of course, those dressed for success will have the best time, or as OffBeat advised: “Sometimes visitors show up dressed for the cocktail hour in Monte Carlo. Utterly deranged madness! Instead, dress as you would for a barbecue in the wilds of Zimbabwe, and you’ll be fine.” Jaz...