If you headed out to your local record store Friday (October 16) to pick up a copy of the "New Moon" soundtrack on the first day of its release, you have a CD packed with fresh cuts from Muse, Death Cab for Cutie, Thom Yorke, the Killers and others. What you didn't get — and what you won't hear unless you download the soundtrack from iTunes — are songs from Lupe Fiasco, APM Orchestra and the Magic Numbers and Amadou & Mariam.

In a post on his MySpace page, Lupe opened up about the creative process behind the track, called "Solar Midnite," and why it's such a unique tune for him.

" 'Solar Midnite' is my first commercial release that I actually produced as well as wrote," he said in the post. "The 'New Moon' team asked me if I could do a song specifically for the film."

That invitation led to an opportunity that would make any "Twilight" fan's head explode: Lupe got to see "New Moon" before its November 20 release date. "They invited me to an early screening of the unfinished film, from which I pulled different elements that I thought would translate into a great song," he wrote. "I pulled in vocalist and bassist Graham Burris and acclaimed musician Matt Nelson to help fill out my vision musically and ... 'Solar Midnite' was born."

Lupe's track, as well as the other iTunes exclusives from APM and Magic Numbers, will play onscreen in "New Moon." The movie, of course, deals with a tricky love triangle between Bella Swan, Edward Cullen and Jacob Black. Lupe's tune taps right into such emotional complications.

"The song basically deals with the chaotic love story that takes place between the characters," he said. "It's more on the rock side of my musical catalog and comes straight from my die-hard fanhood of Red Hot Chili Peppers and Anthony Kiedis, one of my favorite rappers."

Check out everything we've got on "The Twilight Saga: New Moon."

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