The chant of scripture is as distinctive as the religion of the lamas in Tibet.
The Buddhist spirits lives in worshippers spinning prayer wheels at sacred shrines and among pilgrims who prostrate themselves in front of monasteries, keeping count of their solemn devotion with prayer beads.
But the holy Himalayan region is rapidly changing.
Just below the Potala Palace in Lhasa, home to Dalai Lamas for centuries, cars and tricycles cruise the roads lined with office buildings, Chinese shops and massage parlors.
Monks even embrace the convenience of mobile phones.
While lamas debate scripture as they have for hundreds of years, a battle for the hearts of 2.5 million Tibetan believers pits the Chinese government against the exiled Dalai Lama and his followers.
It is a battle China appears to be winning.
It has been 44 years since the Tibetan spiritual leader fled to India, and while many Tibetans still revere him, public display of the Dalai Lama's picture is forbidden.
"[Dalai Lama] advocates independence. That's why we don't encourage the display of his picture here," said the security chief at Tashilumpo monastery, Bazha.
Just whose picture can be displayed is part of the struggle between the Chinese government and the Dalai Lama.
The permitted portrait is of the Panchen Lama, or great teacher, who died in 1989. Below it lies a portrait of the boy the Chinese government helped choose as his reincarnation.
As the new Panchen Lama, it will likely be the job of the young boy to choose the next Dalai Lama after the present one dies.
Although the current Dalai Lama had chosen another boy as the new Panchen Lama, that boy and his family are now in Chinese government custody.
It is an indication of China's success that a 22-year-old monk apparently did not even know about the existence of the second Panchen.
"I've never heard about that," he insisted.
In the palace especially built for the last Panchen Lama, the Chinese government made a room for receiving guests.
But the current Chinese-chosen Panchen rarely goes there, and when he does, he is surrounded by heavy security.
Instead, the 13-year-old spends most of his time in Beijing, far from his homeland and far from believers.
"Beijing offers a better environment for his studies," Bazha said.
Critics say the Chinese government is indoctrinating the boy.
It is difficult to tell just how much effect the struggle for the faith has on the average Tibetan.
A farmer, who displays pictures of the late communist leader Chairman Mao in her living room, told CNN that Mao liberated the Tibetans.
But she also reserves a place in the bedroom altar for a small portrait of the Dalai Lama -- a picture that was quietly put away when CNN crew turned their backs.