Concerto No. 1 in E major, Op. 8, RV 269, "Spring" (La primavera): 1. Allegro is a classical song from one of the four violin concerti titled The Four Seasons by Italian composer Antonio Vivaldi. The Four Seasons were published with eight other conserti as Il cimento dell'armonia e dell'invenzione (The Contest Between Harmony and Invention) in 1725.
In Sing, this song can be heard in the background as Buster Moon discusses his plans for the singing competition with Eddie during a luncheon at Les Calmars.