Back Lot Music will release The Boxtrolls – Original Motion Picture Soundtrack digitally and on CD September 23, 2014, with a vinyl version of the soundtrack will releasing at the end of this year. The album features an original score for the Focus Features and LAIKA family event movie by Academy Award-winning composer Dario Marianelli and an original song by Eric Idle (of Monty Python fame), plus classic songs performed by the group Loch Lomond. The Boxtrolls is the first animated feature that Dario Marianelli has scored, and he began his work notably early in the production process.

"That was a huge benefit for us," said The Boxtrolls co-director Graham Annable. "Dario started work when most of the movie was still in the storyboard phase, and he was able to ask for a few more seconds here and there to let his score breathe – and truly support key moments in the movie. Later, he would also adapt the waltz that he wrote to fit finished shots."

"[Dario] came up with three pieces that, while differentiated, hold the movie together: music for the Boxtrolls' wonderful world in their cavern, music for the White Hats' high-society world in Cheesebridge, and music for the Boxtrolls-snatching Red Hats gang," co-director Anthony Stacchi explained.

The quirky creatures known as the Boxtrolls spend their nights dumpster-diving on the streets of Cheesebridge to salvage thrown out or broken materials, which they then employ to build and fix things in their fantastical underground community. In much the same way, Marianelli employed unusual instrumentation for his score. "The orchestra made use, at one time or another, of a theremin, a saw, a music box, toy piano, dulcimer, accordion, rubbed glasses, washboards, broken light bulbs, forks and knives, and a typewriter," said Marianelli.

A key piece that Marianelli composed is the barbershop quartet track "Quattro Sabatinos." He noted, "One of the most important scenes was also one of the earliest I worked on: the montage sequence during which Eggs is growing up. I had a few goes at scoring it before we all agreed that having that one song going through would help the montage gel together better."

Enhancing the humorous nature of The Boxtrolls with an original song was comedy icon Eric Idle, of the Monty Python troupe, who contributed the words & music of "The Boxtrolls Song."

Idle explained, "I do like telling a story in song. From the artwork that the production sent me, I saw that this movie would have fresh and original characters. In context, this would be a song that the people of Cheesebridge sort of knew. So the song had to have a catchy hook to anchor it as well as quite a strong chorus. I started writing, and playing on my guitar, and came up with something that aimed for a Kurt Weill feel."

"He just nailed it," said Annable. "When you hear the song, the devilish wit in the lyrics marks it as Eric's work. Monty Python was definitely an influence on The Boxtrolls, so we're thrilled to have Eric be part of our movie."

Rounding out the album are three tracks—old and new—from the Portland-based band Loch Lomond. The co-ed sextet distinctly incorporates harmonic vocals, mandolin, theremin, bass clarinet, and all manner of exclamatory percussion minutia to play off the distinct, arresting voice of lead singer/multi-instrumentalist Ritchie Young.

The Boxtrolls will be in theaters nationwide on September 26, 2014.