[This post is based on our Question of the Week #1! Periodically, we’ll feature questions (and their answers) that demonstrate the type of question that we’re extremely interested in having on scifi.stackexchange.com. These questions aren’t just well asked (and answered), but are interesting and worth reading even if you’re not familiar with the work.]
Adrian Petrescu asked “Why do we hear Leia’s Theme during Kenobi’s death?“, referring, of course, to the death of Obi-Wan ‘Ben’ Kenobi in the classic Star Wars (or less-classic Star Wars Episode IV: A New Hope). For those that haven’t seen Star Wars, my apologies for the spoiler (and go watch them all, in whatever order you prefer).
During the film, the composer, John Williams, uses several musical themes (the “Force theme”, “Luke’s theme”, an “Imperial theme”). When Kenobi is killed, when any of those themes would seem appropriate, Williams (and/or possibly Lucas) chooses to play “Leia’s theme” instead, even though there is little connection (especially as known at this stage) between the two characters.
Adrian posits a theory from his music professor:
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.
However, Adrian is doubtful that Williams knew about the familial connection at this time, and so whether he could have been foreshadowing it.
DVK‘s excellent answer references 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 connection to Leia in Episode IV, as far as Williams knew, was not via Luke, but via her father, Senator Bail Organa (“… years ago, you served my father in the clone wars”). DVK also clarifies that Williams could not have known about the Luke & Leia family connection at this time.