What is the shape of sound? OPEN Architecture probes with a monolith chapel

How would sound manifest in architecture? What would its summoned shape be? Dancing lines that swirl with gusto, reaching a crescendo and gracefully dropping, or a mystifying black box of nothingness, where the ping of a piano key paradoxically echoes like a bullet, where unseen tales of love and loathing unfold in a contrasting chorus? What comes to mind when you try to conjure a space that takes on the form of sound and music? Beijing-based architectural office OPEN Architecture delves into the enquiry with the Chapel of Sound, an open-air concert hall conceived as a boulder-like, concrete monolith inspired by its rugged hilly surroundings, a two-hour drive from China’s capital city, defining a new, powerful typology of sensorial design. A tour de force in acoustic architecture, the project’s aesthetic has been made to look “as a mysterious boulder that had gently fallen into place,” the Chinese architects share. 

Nestling itself into a mountainous valley near Beijing, the Chapel of Sound is at one with nature and site, enjoying views to the Great Wall of China built in the Ming Dynasty era. Its entire concrete skin, like darkened charcoal, is enriched with an aggregate of local mineral-rich rocks, helping it seem as a natural being of the landscape, and an enigmatic offering to the same.

Encompassing a semi-outdoor amphitheater, outdoor stage, viewing platforms, and a green room, the recently completed contextual design is composed of a series of concrete layers, created “to capture the unfamiliar and deeply touching experience of music performed in the cradle of nature", both profoundly inspiring and healing. When no performances are planned, the concert hall acts as a tranquil space for contemplation and community gathering, with peaceful views of the sky and surrounding nature.

Li Hu and Huang Wenjing, founding partners of OPEN Architecture, reveal that they were greatly driven by a desire to minimise the chapel’s footprint in the valley, for it to manifest as a striking, spiritual form that would communicate with the impressive natural terrain, "while also feeling undeniably man-made," they say. The resulting building thus is articulated by an inner and outer shell with the space formed in between operating as a truss, achieved with close collaboration with international engineering firm, Arup.

Carrying neither Western nor Eastern thoughts of design philosophy and aesthetic, the shape in concrete features striations that cantilever out from its previous layer, to form an irregular, inverted conical figure. Winding staircases reminiscent of naturally occurring caves and canyons weave through the Chapel of Sound towards a rooftop platform that boasts of panoramic views of the countryside valley and Great Wall, piercingly poetic and grounding. To subtly contrast the grey monochrome of the concrete architecture, accents of warm bronze have been included in the form of handrails and doors inside the myriad stepped hall.

Having spent over 10 years training and working in the United States, Hu and Wenjing have consciously stepped away from traditionally “Eastern” or “Western” ideas of architecture, particularly when it comes to cultural spaces, apparent in this example of Chinese architecture. “OPEN understands that the perceived differences in how cultures experience events and spaces are overstated and through their architecture strive to demonstrate that architecture has the power to connect people with each other, with nature, and with our own past and future,” the design team notes.

We are now at a time when the question of our relationship with nature as human beings is more acute than ever. Can we be humble enough to hear what nature is murmuring to us? The symphony of nature is what we really wanted people to experience here. – Li Hu and Huang Wenjing, founding partners, OPEN Architecture

The open brief for the landmark architecture in China, seems caught between the crosswinds of the past, present and future. The architects researched heavily on all aspects of performance, studying thoroughly how the various behaviours of sound could outline the final shape of the 790 sqm chapel, for which Hu and Wenjing described wanting to “see the shape of sound”.

"Ultimately, they were drawn to the ways sound reverberates in natural spaces such as caves. Having designed theatres and concert halls, they knew the challenge here was how to create an excellent acoustic environment without introducing additional sound-absorbing materials. Working with acoustic engineers, we looked at the many ways people will experience sound in the concert hall and defined openings that act both as the sound absorption areas and providing a connection with the exterior environment,” further adds the design team.

Even in photographs, an inherent air of mystery engulfs the Chapel of Sound, drawing in the eye purposefully on approach. This extends into the dual nature of user conduct, who will ultimately interact with the space, as an individual seeking contemplation versus setting dialogue with the edifice when it becomes host to large-scale concerts. "We wanted the definition of the space to be not so absolute, thus allowing for possibilities. Solitary or communal, music or sound of nature, gazing into the starry sky or connecting with one’s inner self - it’s open to the interpretation of the users,” shares Huang. The effect is furthered inside with schematically cut, geometric openings that open the space to the environment outside on the walls, as well as harnessing daylight through the seemingly misshapen void adorning the rooftop’s centre, to naturally, wholly, and intensely illuminate designated performance spaces, viewed from stepped seating that surrounds the core and merging into the structure's skin.

The sculptural Chapel of Sound also consumes minimum energy, owning to not including heating or air-conditioning in its spatial plan, a purposive decision taken by OPEN Architecture from the very inception of the project. The cutouts seen on the hunk let natural elements permeate the monastic and carefully rugged interior design, reflecting its cool outer skin. Rainwater cascades through the open skylight, trickling down the stepped walls. Drawing from the Pantheon in Rome, OPEN Architecture put a bespoke drainage system in place, to help drain the water away swiftly. The way natural elements are channeled into the structure, where light, breeze, rain and sounds of nature converge majestically inside the choreographed space, demonstrates a pious sense of reverence for nature.

"We were very aware of the responsibility we had to contribute a thoughtful structure that fits naturally into such a unique landscape. We wanted to create something different, and more importantly, something meaningful,” says OPEN Architecture, summing up their spiritually and consciously led approach to the design, playing on the quintessential alliance harboured between music and humanity.

Project Details

Name: Chapel of Sound
Location: Chengde, Hebei, China
Area: 790 sqm
Year of completion: 2021
Client: Aranya International Cultural Development Co., Ltd.
Architecture, Interior Design and Signage Design: OPEN Architecture
Principals in Charge: Li Hu, Huang Wenjing
Project Team: Zhou Tingting, Fang Kuanyin, Huang Zetian, Lin Bihong, Chen Xiuyuan, Cai Zhuoqun, Kuo Chunchen, Tang Ziqiao
Structural & MEP Engineers: Arup
Lighting Consultant: Ning Field Lighting Design
Theatre and Acoustic Consultant: JH Theatre Architecture Design Consulting Company
Landscape Design: Guangzhou Turen Landscape Planning Co., Ltd.