One of those who answered the call was Wang at the age of 15, who then needed to decide which instrument to play. About two years earlier he had lost his sight in a firework accident.

"I recalled the instruments I had seen before I lost my sight, and the saxophone instantly sprang to mind. I consider myself lucky, because when I was young there were few schools that taught music. In many schools for the blind the course that was most commonly on offer was massage."

For his family-he has a younger sister-receiving treatment for his eye condition put considerable stress on the household budget.

"We lived in the suburbs and my music teacher lived downtown and traveling to and from his place once a week for lessons involved hours of bus travel, during which I needed to be accompanied.

"Another problem was that if you want to buy Braille music scores, they're very difficult to find."

That problem is not new, Dou says.

"Visually impaired musicians cannot see musical scores and hearing-impaired dancers cannot hear the music that their partners play. So, it's highly problematic when they want to work together."

The most common way for blind musicians to have access to a score is for assistants to read it out aloud, Wang says. It can then be written down using Braille.

"We don't have conductors, so we need prompts to tell us what we should do," Wang says.

During a performance there are particular players who breathe loudly when they play particular musical sections as a way of signaling others when to start playing, he says.

"Tacit understanding is the key."

Qiang Chuan, who choreographed several performances of the troupe, including Ever-Shining Flower, says:"The dancers, most of whom are deaf, use a little device on their costume that vibrates."