NEW YORK (AP) -- Luscious, harmonious music is swelling from an orchestra in a Chelsea recording studio. The two guys who wrote it listen -- in their own way. They could not seem more different.
On one side of the room is Glen Ballard, rail thin with a mop of unruly, curly hair, wearing a long-sleeved T-shirt and a pair of dark jeans that plunge into boots. He cannot stay still, swaying and stomping and singing to his music.
On the other side is Dave Stewart, seated at a table and intently fiddling with a laptop. He is bearded, his hair is close-cropped and he wears sunglasses, black nail polish, a fedora and a dark jacket. He almost never looks up, lost in the bits and bytes.
It's an early rehearsal for the Broadway edition of the musical "Ghost The Musical," and it represents the final stretch of their latest Anglo-American collaboration after six years of work. They may seem like strange allies at first glance, but the laid-back Yank and the cool Brit have formed an easy partnership.
"I was naive enough to think that we could actually pull this off. And here we are looking at it like we might," says Ballard, a five-time Grammy-winning songwriter-producer who created "Jagged Little Pill" with Alanis Morissette and wrote "Man in the Mirror" for Michael Jackson.
"I walked in with my eyes wide open," says Stewart, the songwriter-producer of Eurythmics fame who has written for Celine Dion and Shakira, among others. "I've been involved in some other things that have been collaborative, but this gets collaborative right down to the color of your buttons on your shirt. I knew it was going to be a long haul."
The musical is based on the 1990 movie in which Patrick Swayze played a ghost trying to communicate with his girlfriend -- played by Demi Moore -- through a fake psychic -- played by Whoopi Goldberg -- in hopes of saving her from his murderer.
The musical has been turned into a stage show with Ballard and Stewart's original lyrics and songs -- except for the classic tune "Unchained Melody" -- and a book by Bruce Joel Rubin, the original screenwriter. The show debuted at the Manchester Opera House last spring and then transferred to London's West End, under the direction of Matthew Warchus.
Ballard and Stewart estimate they have churned out about 40 songs over the six-year process -- with only a little more than a dozen making the final cut -- and for the Broadway run they've added a new one, along with more strings and a French horn. The show is how they like it now.
"I don't think anything's floating through there now that doesn't have a real purpose," says Ballard, whose compares writing a musical to a Rubik's Cube because one change leads to many others. "It's a really serious piece disguised as pop entertainment."
Both say writing together has been fruitfully messy. "What's amazing about this collaboration is if you were to go through the whole score and every song and say, 'Who wrote that bit?' every single one is a mixture of what we've both put in," says Stewart. Or, as Ballard says: "We just get in a room and we start making noise. It's unpremeditated."
Ballard and Stewart, both in their late 50s, knew about the others' work for years -- and had collaborated with a number of the same artists separately, including Katy Perry and Gwen Stefani -- before they met when Stewart moved to Los Angeles in 2006.
Since then, they've collaborated on songs for various artists and scores. Stewart introduced Annie Lennox to Ballard and he produced her solo CD "Songs of Mass Destruction." They wrote the breakout song "Ordinary Miracle" for Sarah McLachlan from the soundtrack to the film "Charlotte's Web."
The dynamic duo are offered projects all the time -- "Today, probably three things already," Stewart muses -- but writing the "Ghost" score intrigued them. They were both fans of the film and of Rubin's 1990 psychological thriller "Jacob's Ladder." The three bonded when they got together.
"When we met Bruce, I think we both warmed to him straightway and him to us," says Stewart. "There was a funny moment when he was talking a lot about the film and I started playing the guitar and actually singing or playing the song he was talking about in his head. He kind of laughed. He was kind of, 'Oh, yeah. That's it. That's what you do.' I was like, 'Yeah, that's what we do.'"
Writing for a musical has been an education for these two rockers, especially the transition parts when actors go from dialogue to song, requiring a suspension of disbelief that even Ballard admits bothers him in traditional shows.
"I'm one of those people who really has a hard time being taken out of a story by a song unless it's really justified," he says, his accent betraying his Southern roots. "Part of it is trying to satisfy that for ourselves."
The way they approached "Ghost" was to pepper the creative team with questions so they could get to know the three central characters better. Sam, the hero, inspired Radiohead-style songs, for example, while spunky psychic Oda Mae Brown's songs are grounded in James Brown and funky soul.
"If we're working with an artist, we really need to know where they're coming from, what inspires them, what their fears are. And, on some level, we had to do the same thing with these fictional characters," says Ballard.
Unlike other rock stars who might toss together a few songs and then walk away, it's clear that Ballard and Stewart have kept careful tabs on the show. Not many men of this stature would spend long days in a threadbare recording studio listening to the conductor and music supervisor tediously pull a new orchestra through song after song.
"Something this complicated and this ambitious, if you think you're going to phone it in, you're shortchanging everybody," Ballard says. "It's a huge commitment. It's kind of an open-ended process until somebody says, 'You have this theater here, 100 feet from Times Square.' I'm going, 'Really? We actually made it to Broadway?'"
"To tell you the truth, I always imagined it, somehow," says Stewart. "I don't know why. I think anybody from Lady Gaga to John Lennon sort of lie in their bed or sit somewhere just picturing themselves at Madison Square Garden or on Broadway or whatever. I don't know why. But you just do. And then suddenly you're there."
That makes Ballard break out in a smile. "I'm living such a charmed life I can't be surprised by anything that happens now at this point," he says. He points out that his last serious involvement in the theater was in high school when he directed a production of "Once Upon a Mattress."
"I'm glad that I have that much experience to draw on," he says, laughing.
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