Blind 'naamyam' singer Tong Siu-yin working to preserve a unique Cantonese artform

Singer Tong Siu-yin comes down off the small stage at a workshop in To Kwa Wan after performing several naamyam songs - the "music of the south" that fans are keen to preserve as part of the city's heritage.

For centuries, the artform was a way for blind people to eke out a living at a time when they were allowed to do little else.

"Throughout the Qing dynasty," Tong says, "they would go and sing in brothels and nightclubs to earn money."

In ancient China, naamyam entertainers would move from village to village singing about the familiar topics of love, but also about everyday issues that might act as warnings or education for the listeners gathered around.

Tong lost most of her sight at 18 months old to a bout of measles and is "officially blind". She declines to give her age - "I won't reveal my secret," she says, smiling in her blue-tinted sunglasses.

While she also sings Cantonese opera, naamyam is harder, she says. Nowadays she is a bit hoarse, but she's still keen to show off a tradition she has been a part of since 2008, accompanied by sighted musicians - a man on the yehu, a string instrument, and a woman on a qinqin, a form of guitar.