Princess Grace of Monaco lovingly narrates this feature-length documentary on the Kirov Ballet School in Leningrad. The film concentrates on three students, beginning with their stern audition—a cattle call where only those with the requisite “dancer’s body” can even survive the first round. From there, it moves slowly through six long, painful and confined years (training comparable to that of an NFL football camp) until the gangly underlings emerge in an explosive yet tremulous graduation performance. Explicit camera work catches the dancers’ subtlest flights and reveals a humanistic Leningrad, contrary to the grim image of Russia. Theatre Street has a soft and informative touch that explains why, although America manufactures the best movies, hamburgers and denim, Russia turns out the best ballet dancers.