SHANGHAI, Sept. 26 -- GU Anping, the city's only blind piano tuner with high-level certification, refines the sound of the instruments with his sensitive ears and deft fingers in a world of darkness.

Born blind in the right eye and almost blind in left, Gu, a 29-year-old Shanghainese, has devoted most of his life to his trade.

He touched the piano keys at the tender age of two, and was unwilling to get off the piano bench since then.

When Gu turned four, his aunt, a pianist in the Shanghai Symphony Orchestra, became his teacher.

After a decade of long practice in a small room without air-conditioning, Gu entered the Shanghai Conservatory of Music, learning piano tuning.

At 15 he played Beethoven so well that he was awarded a 10-level certification for playing piano.

In the first term of tuning class, Gu disassembled a piano into 20,000 parts and reassembled them the fastest of all pupils.

"Piano is not a thing but a life, so treat it as your own baby and you will find the seemingly complicated guy not so complex," Gu said.

"It also has legs, arms and a body.

"What I need to do is to play a role of surgeon, checking every organ and matching them in the right order."

Gu has successfully tuned innumerable pianos after graduation from school at 18, when he suffered prejudice because of his blindness.

"Nobody thought a blind person could tune a piano," Gu said.

All that changed when Gu became one of the city's highest qualified technicians.

Gu soon got an order to tune a big Steinway & Sons piano worth 1.5 million yuan (US$195,000), one of less than 10 in the city. "It is an honor for a tuning technician to make a diagnosis on a Steinway & Sons piano," he said.

Sitting on the bench, Gu lightly flips a key. Instinctively, he feels something wrong and with deft touch he rectifies the problem.

Gu fingers the king of pianos, the Steinway & Sons, and holds his breath.

Then he sits on the bench and plays his favorite sonata ... a graceful tune flows, and a smile appears on his face.