Xuriyanggang, a migrant worker singing duo, part of the line-up of Thursday night's Lantern Festival Gala, have again attracted nationwide attention. After performing at this year's CCTV Spring Festival Gala, they were regarded as the country's hottest grassroots singers. Yet the very song that made them household names, has also locked them in an unwanted dispute. Zhang Nini finds out.

This is the very Internet video that catapulted Xuriyanggang to an online sensation. The migrant worker duo Wang Xu and Liu Gang were filmed singing in their six-square meter rented room last year... unaffected and wild with passion.

"In the Spring", the only song they performed either online or on the CCTV stage earlier this month, can be traced to its rightful owner, Chinese rocker Wang Feng. On February 11th, Wang wrote on his blog that despite repeated suggestions from his company to stop performing the song, the duo continued to use it at various events, including paid shows. Wang has now banned the pair from ever singing the song again.

The controversy has created some public debate.

Cross talk comedian Liu Ying said, "I understood that Wang let them sing the song in the beginning to give them an early start with their singing career. In this sense, they owe a debt of gratitude to their teacher."

But it requires more than a gesture of thank you.

The appearance fee charged by Xuriyanggang has now climbed to 50,000 per show, a number that would be unthinkable if not for their performance at the Spring Festival Gala. Some say they owe this profit from a song they were not legally entitled to sing.

Li Yong, who hosted this year's gala, said that the legal rights must be protected.

Li said, "We should learn to respect copyrights. Everything else is trivial in the face of the law."

Renowned Chinese composer Xu Peidong said he's glad to see an increasing awareness about copyright protection, but he suggests that people shift their focus to producing good and enduring works, rather than the amount of profits it might incur.

Composer Xu Peidong said, "The dispute should not stop us on further artistic creation. Let's look forward, and try to cultivate an environment where arts can prosper."

Xuriyanggang's apology came later on the day on their micro-blog. The duo said that they were sorry, and were thankful for Wang Feng's help and encouragement. Performed a different song at the Lantern Festival Gala this time, Wang Xu believed they will pass through this difficulty.

Wang Xu said, "I believe in my own strength to overcome this eventually."