I've always loved this song. I love it's repetition, its building and its falling - like it's an essay. Everytime I hear it, I'm moved. 

"Fanfare for the Common Man" was certainly Copland's best known concert opener. He wrote it in response to a solicitation from Eugene Goosens for a musical tribute honoring those engaged in World War II. Goosens, conductor of the Cincinnati Symphony Orchestra, originally had in mind a fanfare "... for Soldiers, or for Airmen or Sailors" and planned to open his 1942 concert season with it.

Aaron Copland later wrote, "The challenge was to compose a traditional fanfare, direct and powerful, yet with a contemporary sound." To the ultimate delight of audiences Copland managed to weave musical complexity with popular style. He worked slowly and deliberately, however, and the piece was not ready until a full month after the proposed premier.

Aaron Copland on an American street, Ossining, New York (?), Victor Kraft, photographer (n.d.).   Used by permission of Mrs. Victor Kraft.  Music Division

To Goosens' surprise Copland titled the piece "Fanfare for the Common Man" (although his sketches show he also experimented with other titles such as "Fanfare for a Solemn Ceremony" and "Fanfare for Four Freedoms"). Fortunately Goosens loved the work, despite his puzzlement over the title, and decided with Copland to preview it on March 12, 1943. As income taxes were to be paid on March 15 that year, they both felt it was an opportune moment to honor the common man. Copland later wrote, "Since that occasion, 'Fanfare' has been played by many and varied ensembles, ranging from the U.S. Air Force Band to the popular Emerson, Lake, and Palmer group ... I confess that I prefer 'Fanfare' in the original version, and I later used it in the final movement of my Third Symphony."

Aaron Copland, said the composer and conductor Leonard Bernstein, was the one to "lead American music out of the wilderness." Copland's musical opus, for which he received the 1964 Medal of Freedom, also included such masterworks as "Piano Variations" (1930), "El Salon Mexico" (1936), "Billy the Kid" (1938), "Fanfare for the Common Man" (1942), "Rodeo" (1942), "Appalachian Spring" (1944), and "Inscape" (1967). ( via)