From left to right: Sangpuy Katatepan, Inka Mbing and Ken Ohtake perform at the recent World Musiq festival in Bangkok.

In 1930, the Tayal tribe of central Taiwan fought Japanese colonisers in what is now known as the Wushe Incident. It was Taiwan's final rebellion against the Japanese, and sprang from the treatment of Taiwanese as "aboriginal", lower in class to the komin – the imperial citizens.

This and forced labour and resettlement, and the suppression of tribal practices, fostered resentment among the native tribes.

In a prelude to the battle, an altercation broke out at a wedding when a Japanese officer declined the wine offered him by the groom – the village chief's grandson – and struck the young man with his cane.

Subsequent efforts to make amends by the groom's family were scorned, and the story spread, breeding resentment. When it finally boiled over, the resulting battle left 162 Japanese dead.

Only two Taiwanese died, but 900 were killed or committed suicide amid the retaliation that followed, including those massacred by rival Tayals loyal to the Japanese.

Eighty years later, Inka Mbing of the Tayal tribe and Japanese musician Ken Ohtake found themselves contemplating this story.

With Sangpuy Katatepan from the sea-going Pinumuwayan tribe, they performed at the just-ended World Musiq Festival in Bangkok, leaving Taiwanese in the audience teary-eyed.

Though speaking three different languages, the trio produced "Gaga", a 12-track CD whose songs, they say, reflect "the rhythm of the earth".

Right from getting together, says Inka, "We just felt we were in sync and our message resonated with each other well."

Her words are translated by Cheng Pai Le of the Taipei Economic and Cultural Office, which brought the trio to Bangkok for the festival.

Inka and Katatepan met in 1999 while raising funds for victims of the second-worst earthquake in Taiwan's history, which left 2,416 dead and 11,000 injured.

"When I saw (Sangpuy and his group) sing their own songs, I was struck by it – it means a lot to be able to sing your own songs," Inka says.

Inspired, she returned to her village to find her roots. "We don't have many folk songs. During the Japanese rule we lost a lot of our songs."

Cheng apologises for bringing up the issue to Ohtake, sitting nearby.

"It's okay – it's part of history," he replies.

Inka now composes her own songs, picking bits and pieces from folk songs she learned from her forebears. She frets about the traditional music becoming diluted – or killed altogether by pop.

"We don't sing love songs," Katatepan points out. "Most of our songs are about the relationship between men and nature."

Katatepan comes from the same tribe as popular singer A-mei, who's shared her spotlight with aboriginal Taiwanese but has been criticised for watering down her cultural heritage.

"She's a pop singer," Katatepan says, "but people shouldn't mix up her identity with her music: She's also working for the preservation of her culture."

Inka hopes A-mei too will be able to "sing her own songs" one day.

"Her voice is excellent, but she sings other people's songs. The first time I heard her I thought. 'If only she has an indigenous composer writing for her, it would be better'."

The opening track of "Gaga" is "Linngisan na rgyax" ("Call of the Mountain"), about the 1999 earthquake. In the CD liner notes Inka comments that large-scale mining carried on despite the quake's devastation.

"I was suddenly overcome by this feel ing, as if the mountains were calling out for help. I wanted to stop this callous harm."

Both Inka and Katatepan grew up learning to respect nature's cycles.

"I hope more people can listen to 'Gaga'," Inka says, "because modern people do things against nature. We should not go against the laws of nature ... because the energy is flowing continuously, and if we do something bad it will flow back to us."

In 2007, before work on "Gaga" started, Inka had heard and admired Ohtake's own album. He'd been performing in Europe, Australia and America with Takashi Hirayasu and had come to Taiwan four years earlier with the celebrated Okinawan musician.

In 2006 Ohtake left Hirayasu and started playing for other Taiwanese traditional  artists, including Lin Sheng Xiang, a Hakka guitarist, singer and songwriter. The following year he was invited to collaborate with Inka.

Of her and Katatepan's music, he says, "They have their own roots. It evokes nostalgia, which is quite interesting for me." Compared to pop, it's "very pure", Ohtake adds.

Ohtake accompanied Inka to her village in 2007. The atmosphere was very pleasant, he says, with the elders speaking to him in Japanese. Inka explains that, to this day, respect for the Japanese emperor prevails in her tribe. One of her grandfathers was Japanese as well, coming to the village to teach.

Inka recalls that day when she and Ohtake came home to perform.

"It was raining everywhere – except on the spot where we played."

They sang "Hongu Utux" ("Rainbow Bridge"), a song about the Tayal tribe's belief that the rainbow is the resting place for departed spirits.

"When we were young we were told not to point at the rainbow because that's where the dead live," she says.

"After I sang 'Rainbow Bridge' with Ken, a rainbow came out and it started to rain."

That day, Inka's ancestors must have stopped to watch her perform with the Japanese musician. And just as they believe in nature, the rain must have been its way of cleansing the blood shed by history.