The Pink Magnolias may be atypical, but they’re certainly no novelty act. The Japanese three-piece is the real deal, with a background as solid as anyone on the music scene.

Keiko Komaki started studying classical piano when she was 5 years old and started playing New Orleans music two decades later in Japan. “I saw the Wild Magnolias at the Tokyo Blue Note. That blew my mind,” she said. “I moved here right after Katrina—followed them to New Orleans. They were the first band I sat in with....