As a Michigander, I am fascinated by Mardi Gras culture, and as a non-TV watcher, I'm vaguely familiar with the "Treme" series. On this year's (fourth-annual!) visit to Carnival, I was pleased to see the signage for this temporary exhibit at the Ogden. "Well Suited: The Costumes of Alonzo Wilson for HBO’s Treme" is alone worth the admission fee.
Very spacious galleries, well-displayed. I also sew and create costumes; it was a true joy to get up close to these garments/works of art. I took many photos. It's unlikely that I will ever stumble across the Mardi Gras Indians in person, nor traditional Cajun MG attire. Horizons: broadened.
On a lower level was a display of "realist" paintings by Michael J. Deas, whose submissions have appeared on US postage stamps and the opening credits of Columbia Pictures. Again, it was a pleasure to be able to view the pieces at bifocal distance.
Much more somber was a display of B&W photographs entitled A Chorography of Violence in Orleans Parish. Moving, touching, and thoughtful.
Other reviewers have mentioned the staff. I entered with a mobility device, and the security guard suggested that I check it. Um, no, I'm using it.
Another good stop is the Museum of the Confederacy right next door (I visited and reviewed it last year). If you're waiting out a rainstorm, see both.