Security backed us up. “A band’s going to be coming through here.” As if people wouldn’t think to get out of the way when a brass band was approaching, but this was the Friends of New Orleans All-Star Jam-balaya in Denver, Colorado on the eve of the Democratic National Convention. The 2,000-plus attendees in the Fillmore were delegates, lobbyists, politicians dotted with the occasional music lover, and in the cocktail party-like atmosphere, maybe it would take a...