Dance and instruments

To bring the music-themed murals of the Mogao Caves closer to the audience, Tan inserts a performance of Playing Pipa Reversed into the work.

An apsara (a fairy, or feitian in Chinese), dressed in white, dances along while playing a gourd pipa. The dance, which lasts about four minutes, demonstrates more than 20 poses from Tang-Dynasty (618-907) murals, according to Chen Yining, the dancer.

"The poses are from the murals, but the moves linking each pose are created in a way to make the audience feel like the apsara is flying out of the painting to perform in front of them, as requested by Mr Tan," Chen says.

The gourd pipa, which weighs 450 grams, has been grown and made to look exactly like the version in the murals.

Tan has even commissioned a replica of xiqin, an ancient two-stringed bowed instrument which he saw in one mural, specifically for Buddha Passion, with a specialist instrument maker.

To him, it's worthwhile. Making ancient instruments is "very hard and slow, but very unique", he says.

In addition to pipa and xiqin, Tan has also included elements of organic music, such as the sounds of singing bowls, water, bells and stones, in the symphony.

The choirs

Emma Secher and Rylan Holey, both members of the London Philharmonic Choir, have been tasked to ring bells and play stones, respectively, with other members of the double choir at certain points during the performance.

"It's really amazing; he uses so many percussion techniques," says Secher.

"It's intelligent in terms of his music. It's quite often single track, but his round of music is magnificent," Holey adds. "It's very rare for us to sing with a living composer, to be conducted by someone who is so well-known, so well-regarded. His musical repertoire is astounding."

Both feel that it has been a challenge for the choir because they are not used to singing in Mandarin (with pronunciation marked in the script), but the fusion of Eastern and Western musical traditions works very well.

"It's a very accessible piece. I think it's going to really connect with people," Secher says before a rehearsal session.

Holey says that Tan inspired them to look at the murals in Dunhuang. "I would love to visit Mogao Caves to see all the context of the music, to see the murals and understand what it's all about."

The connection

This may be one of Tan's purposes for Buddha Passion, for it to be a bridge between the Mogao Caves and London, as well as other places in the world.

"I try to connect this ancient wisdom with the attitude of the future and am honored to bring my musical reflections to London and share my Buddha Passion," he says in a trailer on the London Philharmonic Orchestra's website.

"My goal to look back at the past is for the creation of the future," Tan explains. "So that's why you look at this orchestra, although it's a Western orchestra, it's actually reflecting the future.

"You have to understand that symphony orchestra is the only media in our human history that combines institutions, conservatories, art schools and academies of all kinds."

Tan says that symphony orchestra is no longer a Western genre; it's a medium of human history.

"It means it is a global system for sound. That's why I found it very important to write this work in symphonic form, to make every country talk about and share this interesting piece of music."