Parlez-vous free jazz? In almost any other French-language city in the world, this inquiry would translate as: “Do you speak cutting-edge jazz?” But at Canada’s 44-year-old Festival International de Jazz de Montreal— better known as the Montreal Jazz Festival — the question is deceptive in several ways. A majority of the performances at this 10-day summer music marathon in the French-speaking province of Quebec’s largest city are completely free of charge. And while the 2024 lineup will feature such jazz favorites as pianist Jason Moran and saxophonists Joshua Redman, Chris Potter and Melissa …