46 Chapel of Sound

For delivering an acoustical oasis—and economic boost—to a remote community

The Chapel of Sound may look like a prehistoric boulder that somehow landed near the remains of China’s Great Wall. But that belies the serious project planning that went into creating the nature-inspired concert hall. Nestled in the shadows of Ming Dynasty-era ruins in the valley of Chengde, China, the venue is an engineering and acoustic marvel—no less impressive when the hall is empty than when filled with music.

Part of the local government’s efforts to attract tourists to the remote area, the open-air concert hall was commissioned by development company Aranya and designed by Beijing’s Open Architecture.

“We were given an almost completely unrestricted brief and carte blanche to define the scope—and location—of the structure,” says Open Architecture co-founder Li Hu. Such freedom “opened up a unique opportunity to explore ways to ensure the design would fit, and reinforce, the unusually desolate context in which it was situated,” says co-founder Huang Wenjing.

But project leaders had to navigate strict parameters that came with building near the Great Wall. Open Architecture and Aranya chose a flatter part of the valley to maximize views and maintain a respectful distance from the historic structure. That same ethos drove the team to limit the footprint, settling on a relatively modest 790 square meters (8,503 square feet). 

Structural and engineering giant Arup worked closely with the team to design the hall’s amphitheater, stage and viewing platforms—figuring out ways to finetune the vision to minimize materials and bulk. JH Theatre Architecture Design and Ning Field Lighting collaborated on acoustics and lighting, respectively, for the concert hall’s cavernous interior. 

For the building’s shape, the team opted for an inverted cone that resembles a deeply striated boulder, with observation deck cutouts throughout. The tapered structure was built using an aggregate of crushed local rocks and concrete to mimic the valley’s craggy, sedimentary rock formations while also reducing material consumption. Turning the geometrically complex design into a structure that could actually be built required close collaboration between design and engineering right from the start. Arup’s structural engineers used a 3D scanned file of Open Architecture’s model to fine-tune the design. One big challenge? Getting the thousands of timber plates—in different shapes—to fit together like a jigsaw. And then there were the 10,000 rebars—again, all different—that had to be bent and fixed into position.

The team knew it couldn’t skimp on sound, of course. So it used digital optimization technology when designing the concert hall—a space inspired by the contours of shells, wooden instruments and the human ear. Openings in the roof and walls were strategically placed to reduce echo and reverberations, while welcoming in the natural sights and sounds beyond, with songbirds and cello strings mingling at times.

Construction began in April 2018, though pandemic-related delays slowed the schedule by more than a year. In August 2021, the team was finally able to kit out the interior, adding details like bronze handrails along the winding stairs leading up to the roof. And in October 2021, the Chapel of Sound was completed, offering visitors a unique experience, come rain or shine.

“When the sun is shining, the hall plays with sunlight in addition to sound, as sunbeams travel across its cave-like surfaces,” says Huang. “When it rains, water can enter the hall through the central opening, and falls onto the floor in a meditative spectacle before being drained away by floor channels.” 

Even when there’s no performance scheduled, nature puts on a show.