The Atlantic Group and Chop Shop Records hope that today’s anticipated big opening for Summit Entertainment’s “Twilight: Breaking Dawn – Part 1” is a wedding gift of sorts for their latest franchise soundtrack album.

Director Bill Condon’s penultimate installment in the five-film saga, which features the long-awaited nuptials of heroine Bella Swan and her vampire swain Edward Cullen, is accompanied by the latest compilation in the series, which reached stores last Tuesday.

The “Breaking Dawn” album sports a noticeably softer sound than its predecessors. Its lead singles – Bruno Mars’ “It Will Rain” and Christina Perri’s “A Thousand Years” — are both lush ballads, and the set emphasizes boy-girl duets by such young acts as Angus & Julia Stone, Cider Sky, Imperial Mammoth and Aqualung & Lucy Schwartz. Past collections, and “Twilight” author Stephanie Meyer’s blog “playlists,” have flexed a harder sound. No Muse is to be heard this time around.

Chop Shop’s Alexandra Patsavas, the series’ music supervisor and the album’s co-producer, notes, “This is a wedding movie. They’re growing up, and the story and the sound of the movie reflect that… This is the culmination of our love story, so duets seemed to be particularly apropos.”

Paul Katz, album co-producer, head of Eye2Ear Music and Summit’s music liaison, adds, “Because it’s more romantic – there are wedding scenes and newborns and all that stuff – it felt like the right thing.”

The material on “Breaking Dawn 1,” which could appeal to the young femme “Twi-hards” who fill theaters for each installment, is a potential corrective to diminishing soundtrack sales.

Domestically, each succeeding “Twilight” release has sold about 50% of its predecessor. The original “Twilight” package debuted at No. 1 in 2008 and has shifted nearly 2.7 million. In 2009, “Twilight: New Moon” also bowed at No. 1, but has moved 1.2 million. Last year’s “Twilight: Eclipse” arrived at No. 2 and has sold around 575,000.

“This one’s going to alter that course,” says Atlantic Group chairman-COO Julie Greenwald. “We were very late on our music [for “Eclipse”], so we didn’t have the most amazing set-up…On this one, we were really ahead in getting music delivered at the end of August. And we have a campaign where we going to be constantly dropping bombs from now until Christmastime.”

Atlantic was way in front of the pic’s premiere with Mars’ single, which dropped in late September; a YouTube post of the song had scored nearly 14 million hits by late October. It was a multiple-format top 20 hit weeks before the film’s bow.

Says Katz, “We wanted to make sure there was an appropriate corridor for Bruno, because that’s the big single for the movie, and our first priority.”

Music has been an intrinsic part of the ramp-up to the opening. The week of Nov. 7, Perri, whose single arrives this month, appeared at promotional events in Atlanta, Chicago and Dallas with some cast members. Dates in San Francisco and Salt Lake City paired Aqualung & Lucy Schwartz and Sleeping at Last with the film’s players.

Summit’s Nov. 4-6 “Twilight” fan convention at the Hyatt Regency Century Plaza in L.A. featured a karaoke night appearance by actress-singer Mia Maestro – the film’s vampiress Carmen – who contributed the song “Llovera” to the album. “She submitted a track to Bill [Condon], and Bill loved the track, and so did we all,” Patsavas says.

Some lucky Twi-hards received their own serenade this week: Greenwald says, “Summit invited our artists to perform in Los Angeles when all the kids were camped out the weekend going into the premiere. In a way, it’s kind of like entertaining the troops.”

Music for Screens: Fall 2011

WME composer arm changes dynamics | Morris leaps from TV to immortality | Pop icons plys pic trade | Licensing switches from the cart to the horse | Rock royalty acts as one-man band | ‘Dawn’ LP aims to get back on ‘Twilight’ track | Format: From supes to nuts | ‘Anarchy’ keeps humming with eclectic cues | Alt-rock hep cats make ‘Portlandia’ sing | Movie musicmakers