The two master flautists present at the Him Sophy School of Music this week represented the two contrasting faces of the unusual Magic Flute opera currently being rehearsed.

Him Savy was playing a long and silver Western flute, producing pure, high notes. Her contemporary, Keo Dorivan, sat on the floor nearby playing the khloy – a bamboo duct flute whose wavering melody evoked the traditional sounds of Cambodian pin peat orchestras.

The production is a huge undertaking: already half a decade in the making, the full performance isn’t scheduled to take place until early 2018. Its projected budget is $1.5 million.

Spearheaded by journalist and music-lover Robert Turnbull, it will culminate in a 100-plus cast of Cambodian and international performers taking to a makeshift stage at the Chausay Tevoda temple inside the Angkor complex. To convey the tale of Prince Tamino’s quest to win the hand of Princess Pamina, there will be dancers – both classical and contemporary – circus performers, and shadow puppetry.

A 35-piece orchestra is being drafted in from the prestigious Yong Siew Toh Conservatory in Singapore.

“It would have been much easier just to import a production, but I always had this thing that Cambodian musicians need to have a chance,” Turnbull said during a rehearsal break.

“They’re isolated, have low morale ... they want to carry on playing but there are so few opportunities for them.”

He explained that his particular focus was to further the careers of those working in the under-resourced field of Western classical orchestration.

“The [traditional] Cambodian instrumentalists are essentially a professional group ... they’re playing constantly, there’s a demand for that music. With [Western] classical music, there’s very little demand,” he said.

But even with the long run-up to the show, finding Western-trained Cambodian musicians good enough to play alongside one of Asia’s best orchestras had been “a lot harder” than anticipated.

At present, there are five Cambodian musicians – two clarinets, two flutes and a horn – projected to join the Singapore-trained musicians.

It has also been difficult finding operatic singers with the rigorous training necessary to take on Mozart.

“You need to have lessons, the experience; you need to grind,” said Aaron Carpene, music director for the upcoming show.

Carpene said it looked unlikely that any soloists would be local, although there are a few Cambodian-American singers who the directors hope will audition when formal casting takes place this November.

“There’s a chorus, so some of those could certainly be Cambodian,” Carpene added. “We’re still working out what to do there.”

Nonetheless, the performers remain strongly regional: singers from Korea, Vietnam and Thailand have so far been involved, as well as the Singaporean music students who flew in for this week’s workshops.

Carpene explained that the problem was partly down to the fact that Western classical music was never a colonial export to Cambodia.

In Vietnam, the French built two large opera houses modelled on the Opera Garnier in Paris. “There, the French tried to implant opera as a status symbol.”

Turnbull hinted that talented Cambodians were held back by a self-perpetuating cycle created by the current lack of opportunity.

“I spend a lot of time trying to get Cambodians to adopt a professional attitude, but it’s very hard when they have these pressures on their lives ... it’s really quite hard to get them to devote that amount of time,” he said.

Turnbull, Carpene and stage director Stefano Vizioli have found new ways to insert Cambodian culture into Mozart’s 18th-century singspiel. The orchestra will be accompanied by traditional Khmer musicians playing string, keyboard and percussion, as well as Dorivan’s flute, and their music will be used to effect during the opera’s magic interludes. It will also either accompany or replace Mozart’s score at certain points, creating what Turnbull terms a “completely wacky but completely new dimension”.

According to stage director Vizioli, the opera also lends itself to a diverse cast that will create a showcase of Cambodian talent. There is comedy for the circus performers from Phare Ponleu Selpak, and shadow puppetry will be used during Prince Tamino’s trial by fire and water. Vizioli plans to have contemporary dancers from Amrita Performing Arts (who are also line producers for the show) play the flock of the unhappy-in-love bird catcher Papageno.

Mozart at Angkor is not the first time that the potential of The Magic Flute has been picked up on in Cambodia. In 2007, choreographer Sophiline Shapiro used the plot as the basis for new Khmer dance Pamina Devi, although she stripped away all elements of Mozart’s original score.

Vizioli said that he intended to avoid watching Pamina Devi prior to the performance at Angkor. “I don’t want to be influenced,” he said, adding with a cheerful laugh, “First I want to do my own mistakes by myself, and then I will do them with the help of others.”

The workshops that took place this week in Phnom Penh were not open to the public, and concentrated primarily on finding ways to blend the different sounds of the Cambodian and Western orchestra.

Even the visuals of the rehearsal room reflected the scale of the task at hand. On Wednesday, Cambodian musicians sat cross-legged on the floor, the men in starched, gold buttoned shirts and the women in ornate sampots. Behind them, the Western-style orchestra sat straight-backed in their chairs.

But Khmer flautist Darivan, speaking after rehearsals ended, said he was enjoying the experience.

“We don’t discriminate against Western music. I’ve played with Western musicians before, a lot of them, and it doesn’t matter to me,” he said. “It’s like good food made by a good chef.”

Warming to the culinary metaphor, he continued: “It’s like, we used to eat prahok and now we’ve changed to eating French cheese.”