The second Rooney-Garland musical produced under Arthur Freed at MGM, Strike Up the Band veers from Babes in Arms’ Broadway focus to capitalize on the then-growing craze of big band jazz. In the wafer-thin plot, the stars play high school students dreaming of a shot at jazz fame, which eventually comes in the form of a Chicago competition organized by real-life bandleader Paul Whiteman. Newly anointed as the box-office champion of the era, Rooney draws the brunt of the camera’s attention and proves a dexterous showman on a drum kit and a xylophone, while Garland is the shimmying singer carrying a torch for Rooney’s oblivious go-getter. In extensive set pieces such as “La Conga” and “Our Love Affair,” Berkeley works in long, floating takes that find order in disorder, turning the blaring trumpeters on stage and the havoc set in motion on the dance floor into synchronous ballets of cheery movement.