Only a few sounds are as instantly recognizable as the opening swell to the world of a galaxy far, far away: “Star Wars.”  Before a single word is spoken or a lightsaber ignites, the movie that’s become part of American pop culture’s DNA blares its score, resonating across generations.  From the 1977 film, “Star Wars: A New Hope,” to the latest Disney productions, the franchise continues its legacy, inspired by John Williams’ original music. Now, that iconic sound is stepping off the screen and onto the stage as the Colorado Springs Philharmonic performs “Star Wars: The Empire Strikes Back,” accompanying the film in concert at the Pikes Peak Center on Friday and Saturday.  That performance is part of the American Soundtrack Festival, a multi-concert series celebrating the nation’s 250th anniversary through music that has helped define its cultural identity.  Spanning orchestral works, film scores and live performances from world-renowned artists, the festival began April 18 with a…