Of all the mysteries posed by Angkor temples, it is perhaps the people and culture of the empire that most intrigue. What did they wear? What familiar sights and sounds drifted through the immense stone chambers those eight centuries ago?

One small piece of the puzzle will be unlocked this Monday when an ancient harp – the pin – is performed in public for the first time in 800 years.

Like a bass relief coming to life, the boat-like pin has been recreated purely from 12th century images carved on the walls of Angkor Wat and Bayon, and even more remarkably, has so far only been played by the teenage daughter of its maker – 13-year-old Snguon Kavei Sereyroth. Just like the young female musicians in the reliefs.

Made from three types of native wood, animal hide, and silk strings, the harp has a hollow body and long, swanlike neck, similar to the chapey [bass banjo]. In a non-Angkorian flourish, a carved golden dragon and garuda head have been added to the two versions made of it.

Its melodious sound is something between an acoustic guitar and a perpendicular harp – a “Khmer sound” is how instrument maker professor Keo Sonan Kavei, from the Royal University of Fine Arts, describes it.  But therein lies still one enduring mystery – nobody is sure how to play the stringed instrument  or what it should sound like.

Because of this, the team behind it - professor Kavei, renowned composer Him Sophy and French expert Patrick Kersalé – used elements from the Western harp.

“We think about how to play the pin, we thought about the string and the sound,” explains Keo Borivan, musician and traditional music lecturer at RUFA and brother of Kavei.

Born into a family of traditional Cambodian musicians, Kavei has made other ancient harps similar to the Angkorian pin, including one based on carvings at the pre-Angkorian temple of Sambor Prei Kuk, near Kampong Thom. For this harp he has made versions using different materials, including cow hide, brilliant snake skin and sheep skin.

The concept for the recreation of Angkor’s mystery harp has much more recent origins, but has taken more than a decade to come to fruition, explains Him Sophy, who has recently returned from New York along with the Keo brothers, where they performed as part of Season of Cambodia.

“It was my idea to build this harp and compose the music for it, the idea was sparked when I was first studying in Moscow,” Sophy says. “I had this memory of the temples at Angkor, on the Bayon reliefs and walls, the depictions of this ancient harp and other ancient instruments of course, along with inscriptions about the harp. So that was really my inspiration.”

The historical reasons as to why the harp – which is similar in appearance to one found in Burma – is not still played, when other ancient instruments are, are not fully known. Bamboo flutes, cymbals and drums that pre-date the Angkor temples have survived through the centuries to be played in pin peat orchestras, the traditional musical groups that entertained the court – and have evolved accordingly.

Xylophones [roneat] have had an extra set of keys added, to encompass the chromatic scale, and the crescent-moon shaped circle of small gongs, played on the floor, have more than doubled in number since the musician depicted on the Angkorian carvings.

When Sophy returned from the Tchaikovsky Conservatory in Moscow in 1998, he received a grant from the Asia Culture Council in New York, with an idea to release the harp from its ancient obscurity.

“But then I traveled on that program to the US, met John Burt [a Broadway producer and Cambodian Living Arts co-founder] and we had the idea to compose [an] opera…so I still didn’t build the harp!” he says.

“ We performed the opera in Phnom Penh in 2008 and after then a friend asked me again about the harp. We composed Requiem for Cambodia and I really think that piece is perfect for using the ancient Cambodian harp.

“Sonan Kavei had reinvented several ancient instruments already, such as the twin gong and twin roneat - he was perfect to re-make the harp. He collaborated with Patrick, a French researcher and we all contributed drawing sketches and diagrams…”

For the Keo siblings – four of whom teach music at RUFA – their dedication to reviving traditional Khmer music is up to the challenge of incorporating a brand new instrument – one only their very distant ancestors might have played.

“[First we thought] how can we do this? After we made it, we thought, ‘how can we play it?’”, Kavei says. “Not even our grandmother or grandfather knew how to play it.”

So far only Sereyroth has plucked the silk and nylon strings of the pin. It will take some time until the new sound can weave its way into the musicians’ musical imaginations, and are “in the thoughts of the song”, Kavei says.

On Monday it will be played in a traditional piece in a special performance at RUFA, finally taking its place at the head of the pin peat orchestra.