Wang, who is in his 50s, has long list of credits including "Sophie's Revenge" (2009), a romantic comedy. "My Lucky Star" is a sequel that he describes as "sort of cat and mouse."

In a studio at the Shanghai Conservatory of Music, Wang and conductor Qian Yu led the RJ Big Band, a local jazz ensemble, to conclude the soundtrack. The producer had wanted something very much like "Ocean's Eleven," with a big-band sound, he said.

Wang has also composed for string orchestra and recorded with the Beijing Philharmonic earlier.

His projects in film, television and documentary include "Charlie's War," the latest Jackie Chan movie "Chinese Zodiac," Disney's "The Game Plan," the documentary "The Lost Children of Berlin," and the animation "Tom and Jerry: The Fast and the Furry."

"Writing music for any genre is always exciting, the music is about story-telling and being able to support the kind of story the producer and director want to tell," he says.

Many composers and their teams can complete three or four full-length feature films a year and fast production definitely can impact creativity, Wang says. "It's the nature of the business."

"But the more time you have to think about the project and to be brought on board in an early stage, the better," he says. "That gives you more connection to the people involved in the movie."

A typical production can take nine months to a year, and producer and director often meet with composers at the very end. Wang says he often has four to six weeks to compose.

"But I always value and welcome the idea of getting in earlier, going to set and seeing what's going on. It gets into my thoughts and helps me think of what kind of melody I should give to the characters."

An is a renowned soundtrack composer who has composed for many Chinese films, TV shows and commercials.

In 2000 An wrote the score for a German film, "Return of the Black Buddha," and he started thinking and working as soon as he got the script.

"Usually in China, composers are invited at the very end," An says. "For the German film, I was asked to go to the set and the whole process took a year."

Typically he has three months for a project, from the moment he is told to the moment the score is composed. He had only two months to write "Wind Blast" (2010) directed by Gao Qunshu.

TV series make more demands on composers than films.

Wang says the business model of fast production takes a toll in creativity.

"I have worked on movies when they give 99 percent of the time and money to the film and 1 percent to the music, and then they say they want it tomorrow. You don't have a choice, you have no time," he says.

A critical problem in the Chinese film music industry is copyright. Composers' works are not well protected from copyright infringement and some composers just "borrow" from other compositions.

"I think it's unfortunate, but I don't think it's hopeless. Things will change here in China," Wang says.

An says that when composing is more profitable, more people will do it and be passionate about it, but to date, music hasn't been the focus of productions.

"You have to have original soundtrack in order to be recognized, and many in China are pirated and nobody buys, so it's still a question of music intellectual property value," An says.

In Western countries, composers are not only paid for their work, but also receive copyright royalties from distribution.