3 ('Rustle of Spring') is a solo piano piece written by the Norwegian composer Christian Sinding (1856–1941) in 1896.
The work's title indicates that its sense of constant motion is symbolic of the excited restlessness of springtime.
The score has some technically challenging sections, but is, for the most part, easier to play than it sounds, with most of the rapidity made up of simply arpeggiated passages.
Its form may be summed up thus: An orchestral version of Rustle of Spring appears as part of the score to Harman and Ising's 1936 Happy Harmonies cartoon The Early Bird and the Worm.
The piece features prominently in the 1939 Hollywood film Intermezzo, first in an orchestral arrangement, and then with its main melody hummed and played on piano by Ingrid Bergman's character Anita Hoffman.