I've always wondered about that comment years ago. Maybe DoctorPadawan remembers?
Here I am, the receptacle of all meaningless minutae regarding the molestation of JW's prequel scores.
I don't remember the exact location of the quote, but I do recall the comment being made by JW that when he first had the LSO play the music from the duel in TPM (which we all know in its concert suite form as DOTF) for Lucas, Lucas told JW that even though he didn't know it, JW had pretty much just written the music for the end duel in Episode III. The comment Lucas makes on "The Beginning" or the last TPM webdoc is (and I'm paraphrasing) "you didn't know this, but that leads directly into the end of Episode III."
Ben Burtt was overheard to say "but nooooo....I've got this wonderful sound effect of a turnip farting I was going to use for a volcanic eruption and it is infinitely more important to the emotional impact of the scene than music! The whole world is sitting on the edge of their seats because of my sound design in the duel! Maybe we can just let the screen go black since I am the most important and memorable thing about Star Wars! Can't we just track music (badly) from somewhere else instead? Hey George, look at me, look what I can do! Look how important I am! WAAAAAAAAAHHHH!"
Uh, yeah...before I went on my tangent there, I do hope that DOTF is used *sparingly* and that JW is allowed to just go wild with the score and include every thematic element related to Obi-Wan, Anakin, Vader, Sidious, the Jedi Knights, the Sith, the love theme, and Luke and Leia's themes as a way of tying everything up musically, not unlike the way AOTC ends with the major players' themes being repeated in succession, but in a totally new way. This is the climactic moment of the entire prequel trilogy and the moment we have been waiting for from a story standpoint since we found out the prequels would become a reality (or since we first read that little comment in the novelizations for the OT way back when about the lava duel), and I think that certain egos should step back and allow the scene and the emotion to bear the true importance of the scene. If it isn't scored by choice, so be it. If it is scored by choice, let JW do his thing. I just hope we don't wind up with a AOTC reel 6 cluster**** again.
But of course it will end up being tracked music from TPM so we can hear the turnip farts, and so we can be treated to more ten minute explanations of the turnip farts on the DVD commentary when you really want to hear Lucas explain why Greedo shoots first now.