A Composer's Dilemma: Write or Recycle?

As I was watching The Spiderwick Chronicles with my sister last night, a movie I'd happily recommend to anyone who loves movies in the fantasy/sci-fi genre, we recognized something rather familiar. It wasn't the fact that child-actor Freddie Highmore played both twin brothers in the movie (an amazing feat for someone of his age and experience), it was rather the score weaving in and out of the background throughout the film.

My sister and I, being avid fans of the '95 film Casper, even seeing it as recently as last week, thought the main melody in Spiderwick was extremely similar to the main theme in Casper. As The first third of Spiderwick completed, I turned to Elissa and asked her "do you -- do you hear the music?" She looked over at me and said "I think... Casper?" Both shaking our heads and dismissing it with "nah, they wouldn't have done that..." we were still oddly preoccupied with what we heard throughout the rest of the film.

Then it hit us: During the end credits (another visual masterpiece to compliment Nickelodeon's previous film Lemony Snicket's A Series of Unfortunate Events), the composer's name appeared: James Horner. If you're a fan of movie soundtracks and composers, you may recognize James Horner also composed Casper.

We were shocked: James Horner recycled and reused his theme from Casper in Spiderwick! Of course, it wasn't a verbatim recycling, it had been updated and masked edited a bit.

Doing some quick researching last night, I found that many avid listeners also picked up on this fact. What would drive a composer to recycle old themes for a new soundtrack? (We'll omit John Williams' constant recycling of his Star Wars' themes for his portfolio of scores for the franchise.)

There are a few reasons that come to mind, but any composer who frowns upon recycling would consider these reasons mere cop-outs: not enough time/too many projects in production, writer's block, lapse in memory, subconcious writing based off an "idea" that's actually a previous work, etc.

According to Wikipedia, James Horner had composed 35 complete soundtracks prior to scoring Spiderwick, so it's entirely possible that he either subconsciously recycled the music thinking it was new or thought that with enough masking and editing, nobody would notice the recycled theme.

Whatever the reason, it got me thinking how many other successful films had recycled music in their soundtracks there were in the past few years.

Can you recall any similar soundtracks out there that go above and beyond the inclusion of a "familiar" or "similar" riff or motif?