Why do we hear Leia's Theme during Kenobi's death?

Question

This was an interesting point brought up by a music professor; by the second third of Star Wars, John Williams has introduced and reinforced a number of musical themes: the "Force theme", Luke's theme, and an Imperial theme. However, at the moment of Kenobi's death (certainly one of the most important moments in that film), when all three of those themes would have been more appropriate (and probably in that order), Williams instead chooses to play a stylized version of Princess Leia's theme.

This is an odd choice; Kenobi and Leia have never even properly met, and she seems downright uninterested in what is happening to him right then. Of course there is an in-universe connection between them, but the audience (and possibly most of the cast) would remain unaware of it for the better part of a decade.

My music professor's pet theory is that Kenobi has taken on a paternal role for Luke and so Williams is co-opting Leia's "feminine" familial theme for the entire Skywalker family, thereby foreshadowing that entire connection. This of course requires that he knew the larger arc of the plot during production of the very first film, which I find doubtful, and I think I've even heard it contradicted somewhere before.

The question is, does anybody have any insight into this odd musical choice? Can anybody explicitly confirm or debunk whether Williams knew enough about the plot at this point in time to have been making such a foreshadowing at all?

Answer 1

1. As far as "why Leia's theme was used for Kenobi's death" part, the most "official" source (short of someone managing to outright pose this question to John Williams) is Michael Matessino's liner notes on RCA release of "Star Wars: A New Hope: The Original Motion Picture Soundtrack":

   ... Interestingly, Williams uses Princess Leia's theme at the moment Ben vanishes, deferring to the purely musical effectiveness of the sweeping melody over any apparent thematic relevance, although the theme does reinforce the connection between the Princess and the old Jedi suggested by her holographic message.

   In other words, Kenobi's "ANH" connection to Leia as far as Williams knew was not via Luke, but via Senator Bail Organa ("... years ago, you served my father in the clone wars", if you recall the holographic message Leia recorded to Obi-Wan in R2D2's memory).

2. To answer your specific question at the end ("whether Williams knew enough about the plot at this point in time"): The answer is NO.

   Williams - at the time of writing the score of "A New Hope" (e.g. prior to 1977) - did NOT know that Luke and Leia are family.

   To be more specific, even an early Leigh Brackett's 1978 draft of "The Empire Strikes Back" didn't have that relationship established yet - it was introduced later (Source: Early Draft Of ‘Empire Strikes Back’ Reveals Alternate ‘Star Wars’ Universe, Geeks of Doom ).

   Another related evidence for Luke and Leia not yet being related was 1978 pre-ESB book that was a sequel to "ANH" - Alan Dean Foster's "Splinter of the Mind's Eye". It develops the theme of romantic interest between the two (presumably, in part, since Foster and Lucas didn't know if ANH would be a big hit and if Harrison Ford would be interested in the sequel should the sequel be based on "Splinter").

Answer 2

From John Williams his own liner notes for the original SW OST.

"For "Ben‘s Death" I used part of the Princess Theme in the beginning. l felt it had the most sweeping melody of all the themes in the score. This wildly romantic music in this tragic setting represents Luke's and the Princess' reaction to leaving Ben behind."

Answer 3

It's possible that Leia's theme was used to remind the audience that her mission is in jeopardy with his death, but also that her mission is in good hands now that Luke is taking the reins from the fallen Jedi Master.