Studies have shown that readers use their background knowledge—vocabulary, facts, and conceptual understanding—to comprehend the text they read. Much of this evidence isn’t new.

Now, an extensive study from the University of British Columbia in Canada shows that students who took music lessons in high school performed better in subjects such as English, science, and math.

The study’s authors represent Harvard Medical School and Brigham and Women’s Hospital in Boston and the University of Alabama at Birmingham. They wrote that they sought to understand which ...