Tremé (spelled by some, including Simon, without an accent), adjacent to the French Quarter, is one of the elsewhere places: largely unknown to outsiders, it’s thought to be the oldest African-American neighborhood in the country and had a large population of free blacks even before the Civil War. Historically, it’s the musical heart of the city, going all the way back to the seventeen-hundreds, when slaves were allowed to gather in Congo Square (now contained within Louis Armstrong Park) to dance and play music.