John Williams' score for Star Wars (1977) single-handedly rejuvenated the orchestral film score; that had not been dominant since the 1930s and 1940s, and is, without doubt, the most influential soundtrack in film history. In the 1970s pop and jazz scores predominated and it was a bold move on the part of George Lucas to insist on a full orchestral score in the style of Korngold, Waxman, Steiner and Newman for his much derided (before its release) science fiction epic. John Williams, at the time, was much better regarded in Hollywood than Lucas, coming off his Oscar for best musical score for Jaws (1975).
Adopting a Wagnerian leitmotiv approach (not heard since Steiner's work) and heavily influenced by Russian composers (particularly Rimsky-Korsakov and Stravinsky) of the early Twentieth Century Williams' score redefined film music for decades to come. The apotheosis of film scores, Howard Shore's Lord of the Rings: The Fellowship of the Ring, simply could not have existed without Williams masterpiece. It is arguable that his second score for Lucas, The Empire Strikes Back (1980) actually is melodically and thematically stronger (the Imperial March is, quite simply, one of the best marches ever composed) but Star Wars is, in a way, a unique achievement; thematically seperate from his other Star Wars scores and the stronger for it.
In a short period Williams' scores for Star Wars (1977), Close Encounters of the Third Kind (1977), Superman (1978), The Empire Strikes Back (1980) and Raiders of the Lost Ark (1981) changed the way that Hollywood thought about film music and Star Wars would go on to become the most popular film soundtrack of all time.
Quite rightly, Williams picked up the Oscar for best musical score in 1978 for his Star Wars soundtrack. Willliams is, jointly with Alfred Newman, the most Oscar nominated person (an almost unbelievable 45 times) in history. He has won five times and, in 2005, his scores for Star Wars (1977), Jaws (1975), and E.T.: The Extra-Terrestrial (1982) (possibly his finest achievement) were respectively ranked number 1, 6, and 14 on the American Film Institute's list of the Top 25 Film Scores in the past 100 years