‘The Marching Band’ Review: Brothers From Opposite Worlds Are United by Music in a Finely Tuned French Crowdpleaser

“The Marching Band” blasts through more story in its first 12 minutes than many films now manage in two hours. In those first 720 seconds we meet Thibaut (Benjamin Lavernhe), a well-heeled classical music conductor in Paris, who discovers that he will need to find a blood marrow transplant as he…