On the fringes of the demonstrations in Hong Kong, one could sometimes observe a bizarre scene over the past few days: an autograph session in which demonstrators dressed in black hold out their goggles or mobile phones to be signed by a tall woman, also dressed in black. They're reaching out to Denise Ho, one of the best-known pop singers in town.

Five years ago, she made a decision that would ban her music from the lucrative Chinese market, losing her a fortune, in exchange for saving her conscience. Since then, she has become one of the most famous faces of Hong Kong's democracy movement.

Ho was born in Hong Kong in 1977. When she was 11, her parents immigrated to Canada. It was the first wave of emigration from Hong Kong caused by a treaty between Great Britain and China. At the time, Hong Kong was still a British colony but both countries had agreed that the city would be returned to China in 1997. Many citizens of Hong Kong were afraid of losing the freedom and prosperity they had enjoyed under British rule.

Ho's family moved to Montreal, where as a child, she became enthusiastic about the pop music in her hometown. She especially loved the melancholic ballads of Anita Mui, who was one of the scene's biggest stars at the time. "That was my connection to Hong Kong, even though I was far away," she explained.

Read more:Donald Trump: Hong Kong crackdown would hurt China trade deal 

The 80s and 90s were Hong Kong's cultural heyday. Jackie Chan's action films drew audiences around the world to cinemas, while the melancholic characters of Wong Kar-wai's films inspired the Western art house scene.

Meanwhile, the pop music of Anita Mui and Faye Wong could be heard around the region, from Mongolia to Singapore. Cantopop, named after the Cantonese dialect spoken in Hong Kong, set a trend in all of Asia. It was a hit in mainland China, where the Cultural Revolution had taken place only a few years prior. There, the stars of Hong Kong conquered the hearts of the Chinese masses with their music, which deals with human desires instead of revolutionary achievements.

When she was 19, Denise Ho returned to Hong Kong to take part in a talent competition on television. She won, stayed in town and began working closely with her idol, Anita Mui. Soon, she herself became one of the stars of the scene.

But then the city began to change. A powerful entertainment industry had developed on the Chinese mainland where the People's Republic produced its own pop culture — compatible with the morals and political taboos of the Communist Party. Hong Kong's actors, directors and musicians were also attracted to the billion-dollar market on the mainland. The city's creative scene began to increasingly merge with the mainland, becoming less and less unique. "Creativity changes when you have to stick to censorship," says Ho.

Ho's image has never been entirely commercial. Her music is often rougher than the classical cantopop. And in 2012, she was the first pop singer in Hong Kong to come out publicly as a lesbian. But she wasn't exactly a rebel who broke the rules of the entertainment market. She, too, celebrated success in mainland China. In 2010, she released her first album in Mandarin, the language spoken in the People's Republic and Taiwan.

Then, in 2014, the yellow umbrella movement paralyzed Hong Kong for weeks as protesters flocked to the streets. Ho declared her support for the young demonstrators and performed a solidarity concert in their honor. In China, her music was immediately blacklisted and her songs disappeared from all streaming services. She said she knew that it meant the end of her career on the Chinese mainland, but that if people were going through a crisis like the one in Hong Kong, then one has to make decisions.

Read more:Hong Kong protesters march in peace after weeks of chaos 

China requires stars who want to be successful on the mainland to stick unconditionally to the party line — and just one wrong click on social media can mean the end of a career.

Last June, Hong Kong actress Charmaine Sheh "liked" a photo of the mass demonstrations. It caused and uproar and the actress was pulled from Chinese networks. She quickly apologized, writing on social media: "I love Hong Kong and I love China." Whether the Communist Party and the nationalist Internet scene will accept her apology as sincere and grant her the grace of market access once again, remains to be seen.

Denise Ho says that she can no longer imagine living a life where she has to think about the consequences of every "like." But her commitment to the democratic movement has put her existence as a musician to the test. She lost sponsors and her record label ended their collaboration. She now has had to produce her own music, develop marketing strategies and organize concerts. "I first had to learn how much administrative effort is behind a successful career," she says. The floor of a factory on the outskirts of Hong Kong is now her office, rehearsal room and recording studio.

Five employees sit around a large wooden office table. Ho examines the plan of the Hong Kong Coliseum, the largest concert hall in the city. The venue is owned by the city, and her five previous requests to book it were rejected with no explanation offered. Now, for the first time in 2014, she will have a concert there.