Appalachian Spring is a ballet score by Aaron Copland that premiered in October 1944, and achieved widespread popularity as an orchestral suite. The ballet, scored for a thirteen-member chamber orchestra, was created at the request of choreographer and dancer Martha Graham and commissioned by Elizabeth Sprague Coolidge. While writing the work over the course of a year, Copland wrote that it was somewhat foolish to do as the ballet and its corresponding scores were historically short-lived ^{citation needed}. Copland was awarded the 1945 Pulitzer Prize for Music for the ballet.

The story told is a spring celebration of the American pioneers of the 1800s after building a new Pennsylvania farmhouse. Among the central characters are a newlywed couple, a neighbor, a revivalist preacher and his followers.

In 1945, Copland rearranged the ballet work as an orchestral suite, preserving most of the music. The ballet and orchestral work were well received. The latter was credited as more important in popularizing the composer. In 1972, Boosey & Hawkes published a version of the suite fusing the structure of the orchestral suite with the scoring of the original ballet: double string quartet, bass, flute, clarinet, bassoon, and piano. All three versions continue to be performed in full.

The orchestral suite is divided in eight sections, which Copland describes as:

1. Very slowly. Introduction of the characters, one by one, in a suffused light.
2. Fast. Sudden burst of unison strings in A major arpeggios starts the action. A sentiment both elated and religious gives the keynote to this scene.
3. Moderate. Duo for the Bride and her Intended – scene of tenderness and passion.
4. Quite fast. The Revivalist and his flock. Folksy feeling – suggestions of square dances and country fiddlers.
5. Still faster. Solo dance of the Bride – presentiment of motherhood. Extremes of joy and fear and wonder.
6. Very slowly (as at first). Transition scene to music reminiscent of the introduction.
7. Calm and flowing. Scenes of daily activity for the Bride and her Farmer husband. There are five variations on a Shaker theme. The theme, sung by a solo clarinet, was taken from a collection of Shaker melodies compiled by Edward D. Andrews, and published under the title "The Gift to Be Simple." The melody most borrowed and used almost literally, is called "Simple Gifts."
8. Moderate. Coda. The Bride takes her place among her neighbors. At the end the couple are left "quiet and strong in their new house." Muted strings intone a hushed prayerlike chorale passage. The close is reminiscent of the opening music.

The seventh section, which is a set of variations on the Shaker melody known as "Simple Gifts", is the most recognizable section from the ballet, and has been featured in many television commercials. Copland published independent arrangements of this section for band (1958) and orchestra (1967) titled Variations on a Shaker Tune. Each variation takes the simple theme with changes limited to key, accompaniment, register, dynamics, tone color, and tempo. The second variation provides a lyrical treatment in the low register while the third contrasts starkly in a fast staccato. The last two variations of this section use only a part of the folk tune, first an extraction treated as a pastoral variation and then as a majestic closing. In the ballet, but not the suite, there is a lengthy intermediary section that moves away from the folk tune preceding the final two variations.

Originally, Copland did not have a title for the work, referring to it simply as Ballet for Martha. Shortly before the premiere, Graham suggested Appalachian Spring, a phrase from a Hart Crane poem, even though it has no direct relation to the story of the ballet. Copland was often amused when people told him he captured the beauty of the Appalachians in his music.

Appalachian Spring premiered on October 30, 1944, at the Library of Congress in Washington, D.C., with Graham dancing the lead role. The set was designed by the Japanese American sculptor Isamu Noguchi.