Williams wrote scores for all six of the Star Wars films between 1977 and 2005. His scores for the double trilogy count among the most widely known and popular contributions to modern film music. For the grand symphonic scores of the Star Wars films, Williams revived a technique called leitmotif, which is most famously associated with the operas of Wagner and, in film scores, with Steiner. A leitmotif is a phrase or melodic cell that signifies a character, place, plot element, mood, relationship or other specific part of the film. Of chief importance for a leitmotif is that it must be strong enough for a listener to latch onto, while being flexible enough to undergo variation and development.
The Main Theme appears in all episodes and is the anthem of the saga, easily the most recognisable melody and is associated with Luke, heroism and adventure. It is heard over the opening crawl at the beginning of all the films and forms the basis of the end-title as well.
The lushly scored Princess Leia’s Theme represents the romanticized, somewhat naïve idea of the princess. It is most often heard in Episode IV, but is used in the next two films when she is acting on her own, when she is particularly vulnerable, or when she is mentioned.
The Imperial March or Darth Vader’s Theme represents the totalitarian Galactic Empire as a whole and Darth Vader specifically. The March has attained an iconic status in the Western consciousness as a general ‘evil theme’. Musical features include relentless martial rhythm and dark, non-diatonic harmonic support.
Yoda’s Theme is a gentle melody for the Jedi Master who appears in five of the six films along with his music. The theme is closely associated with his teachings and abilities though can be related to Luke’s retention of those lessons as well.
The Throne Room (from Episode IV) and end titles. Williams created an extended version of the ceremonial music heard at the end of the original film. It has not been included on a Star Wars soundtrack. However, Williams incorporates this version into the full end credits of the Episode III soundtrack, although it was cut from the theatrical print of the film, probably because it is six minutes long.