As amsco15 mentioned an upcoming NOLA trip (jealous here) I posted a list of Jazz venues off the beaten path. The list was provided by two acquaintances, on the NOLA Jazz scene:
Some of these are rather casual, operated by players that curate for several clubs, and at least one is music played on their porch. In general these tend to offer Jazz reflecting the current scene, unlike Bourbon Street, which caters to the casual music tourist.
Regardless enjoy your trip amsco15!