Hong Kong Chinese Orchestra join forces with a cappella Yat Po Singers in theatre production

Anyone who has seen the Yat Po Singers in action knows they are more than just an a cappella ensemble. Like other modern harmonisers, the four-man outfit - Keith Wong Chun-kit, Ronald Tsang Ho-fung, Raoul Chan Chi-him and Sam Lau Siu-hong - deliver inventive mash-ups of songs from classical to jazz and more. And being Hongkongers, they bring Canto-pop, Chinese folk and Peking opera into the mix, too.

But beyond the vocal gymnastics, what sets Yat Po apart is their physicality and incorporation of theatre. That's because the troupe began as a cross-disciplinary experiment by choreographer Yuri Ng Yue-lit, composer Ng Cheuk-yin and choral director Patrick Chiu Pak-shing.

Rock Hard, their first production in 2008, gave an indication of the direction they were taking. A quirky take on local folk tales (the title refers to Lion Rock rather than headbanging), it featured a 19-man chorus whose voices served as choir and orchestra, supported by a lone female dancer.

Since then, Yat Po have staged three full-length productions and collaborated with local dance and stage veterans, as well as emerging Cantonese opera talents.

The collaborations continue this weekend at performances in combination with the Hong Kong Chinese Orchestra. Titled Herbal, Vocal or Motional?, it is a light-hearted exploration of concepts in traditional Chinese medicine mixing storytelling, movement and fresh arrangements of familiar tunes.

"It'll certainly be an unusual concert experience," says an enthusiastic Yan Huichang, artistic director of the Chinese Orchestra.

Seeds for their collaboration were planted two years ago after he saw a performance of Sing Sang Sung ,Yat Po's second full-length production. He was impressed by the holistic theatrical experience and how a cappella arrangements were combined with the sheng, a traditional reed instrument.