NEW ORLEANS — Régine Chassagne was standing barefoot in her rambling New Orleans home on a recent weekday, showing members of the Preservation Hall Jazz Band how to play the horn parts for her latest musical project.

It was a galloping Carnival anthem played in the Haitian style and sung largely in Haitian Creole, a language the jazz players did not understand. Ms. Chassagne, a Canadian-born daughter of Haitian exiles, described their parts with swooping hand gestures. At one point, she told them to play “like fireworks — poof!”

The jazzmen, masters of translating emotion into sound, nodded along, unfazed.

Ms. Chassagne, 41, is a founder of the rock group Arcade Fire, a French speaker of mixed racial heritage who grew up in Montreal playing the piano to old Louis Armstrong recordings. More recently, she has become a prominent advocate for the Haitian people and for a Haitian culture that has had an outsize, if not always recognizable, influence on New Orleans, where she and her husband, Win Butler, have lived for about three years.

For this year’s Carnival season, the period of revelry before Lent, Ms. Chassagne and Mr. Butler, the Arcade Fire frontman, will highlight their adopted city’s Haitian connections with the kind of primer its residents readily understand: a raucous procession by the couple’s Haitian-themed Mardi Gras troupe, the Krewe du Kanaval. Founded in collaboration with the New Orleans jazz hub Preservation Hall and rounded out by local and Haitian musicians, the krewe plans to parade through the streets of the French Quarter and Treme on Tuesday, a week before Mardi Gras, and put on a free street party.