New Orleans Duets, Tom McDermott’s new album, was over five years in the making. The album is a collection of duets with people you might expect—Evan Christopher, Matt Perrine, Tim Laughlin—some that make sense—Helen Gillet, Michael Skinkus, Anders Osborne—and some you didn’t see coming, Louis Armstrong and Jelly Roll Morton included. “I wanted to do this album since before Katrina, but I got distracted,” McDermott says. “I really wanted to do the Brazil album, and that took a year. ...