Inside the Syrian capital's Great Umayyad Mosque, six muezzins sit before a loudspeaker, collectively reciting the call to prayer that can be heard across the ancient quarters of Damascus. They are among 25 muezzins who take shifts intoning the azan, or call to prayer, in groups, using a technique of collective recital that is unique to the centuries-old mosque. The place of worship was closed in mid-March as part of measures to stem the novel coronavirus pandemic that Damascus says has infected 29 people, two of whom have died – but its calls to prayer live on. Mohammad Ali Al Sheikh, the eldest of the muezzins, said the tradition runs in his blood. "I come from a long line of muezzins," the man in his eighties said. "I have been a muezzin for 68 years, as was my father until he died." Muezzins may have day jobs or be retirees but are all selected for their extraordinary voice. Mr Al Sheikh was drawn to the role as a child, encouraged by his father's colleagues who complimented him on his voice, one he now cherishes as a gift from God. "God prepares the muezzin with a voice, one that is gifted to him, to elevate God's word," he said. In a room inside the mosque, a picture of the sacred Kaaba, Islam's holiest site in Mecca, Saudi Arabia, hangs near framed verses of the Koran holy book. Mr Al Sheikh raises the call to prayer, with five other muezzins chanting along in unison, using the technique known as Al Jawq. It yields a unique sound when it rises from the Umayyad Mosque, which sends out the azan from three towering minarets overlooking the capital. Built in the eighth century, the Umayyad Mosque has long drawn in worshippers near the Damascus centre's Hamidiyah souk, or bazaar. Before loudspeakers were installed in the 1980s, groups of muezzins used to recite the call to prayer directly from the minarets, Mr Al Sheikh among them. Amplifying their voices so they could be heard across Damascus, they also raised a red ball to alert other muezzins in the city to join the call to prayer, Mr Al Sheikh said. There are many accounts of how the group call to prayer started at the Umayyad Mosque but its muezzins say that it was born out of a need to reach as many worshippers as possible. In his book, "The Great Mosque of Damascus", architect and writer Talal Akili said the technique originated in the late 15th century as a way to inform Muslim pilgrims converging on the city en-route for Mecca that it was time to pray. With decades of experience, Mr Al Sheikh is among the muezzins qualified to grant certificates to pupils training to recite the azan. "The muezzin's voice must first be beautiful and loud, and after that, he must learn to recite and intonate," Mr Al Sheikh said. A certificate is granted when a pupil masters the "rhythm and rules of the call to prayer", he added. A nephew of Mr Al Sheikh, Abu Anas, is also a seasoned muezzin, having recited the call to prayer every day for 10 years. The tradition "has been passed on from father to son, for at least five generations", he said. "It's not a hobby, it runs in our blood." His grandfather was the lead muezzin in Damascus, and when Abu Anas was just a child, he used to watch his father recite the call to prayer from the Umayyad Mosque, famed for its columned courtyard and walls covered in golden mosaics. At other mosques in Syria a single muezzin usually performs the call to prayer. But at the Umayyad Mosque, only the dawn call is performed by a sole muezzin. Even at the height of Syria's war, now in its tenth year, the Umayyad Mosque remained open. The move by authorities to shut the mosque last month over the coronavirus stunned many Damascus residents. But muezzins like Muhammad Al Saghir continue to call worshippers to pray – although now the faithful do so at home. The 51-year-old sells silver from a small shop a few metres from the Umayyad Mosque, in the Qaymariya neighbourhood. While answering questions from customers about the prices of items on display, he eyes a watch hanging on a wall in front of him. When it is time to pray, he closes the shop, apologising to clients for his absence, and walks to the Umayyad Mosque to intone the azan. "People understand. Even my Christian clients ask me to pray for them," he said. Working nearby and with his vigilant observance of prayers, Mr Al Saghir grew close to the muezzins in the Umayyad Mosque long ago. Impressed by his dedication, they encouraged him to join their ranks, and even though he was not formally trained, he started reciting the call to prayer in the 1990s. It has since become a priority in his life. "Worship is continuous renewal. It brings us closer to God," he said. While he is bound to retire one day from the silver trade, he said he would continue to be a muezzin until the day he died, cherishing the tradition as part of Syria's national fabric. "I am proud that I am a muezzin at the Umayyad Mosque," he said. "This is Syria's heritage."