How a Historian Stuffed Hagia Sophia’s Sound Into a Studio

Turquoise carpets covered the marble floor, with its geometric designs. White drapes concealed the mosaic of the Virgin and Christ. Scaffolding obscured crosses and other Christian symbols.

Footage broadcast around the world last week captured some of these striking changes to Hagia Sophia, the Byzantine cathedral in Istanbul, which served as a mosque under Ottoman rule before becoming a museum in 1934. On the orders of Turkey’s president, Recep Tayyip Erdogan, it is now once again used as a mosque.

But for a group of scholars, scientists and musicians, Hagia Sophia’s rededication as a Muslim place of worship threatens to cloak a less tangible treasure: its sound. Bissera Pentcheva, an art historian at Stanford University and an expert in the burgeoning field of acoustic archaeology, has spent the past decade studying the building’s extravagantly reverberant acoustics to reconstruct the sonic world of Byzantine cathedral music. Ms. Pentcheva argues that Hagia Sophia’s mystical brilliance reveals itself fully only if it is viewed as a vessel for animated light — and sound.

“The void is a stage,” she said in a recent interview over Zoom.

Conducting research inside this contested monument has required a mixture of diplomacy, ingenuity and technology. Turkish authorities forbade singing inside Hagia Sophia, even when it was operated as a museum. Now that the building falls under the jurisdiction of religious authorities, that ban will harden, and further research may be even more difficult.

But Ms. Pentcheva’s existing work culminated last fall in the release of “The Lost Voices of Hagia Sophia,” an album that brings to life the stately mystery of Byzantine cathedral liturgy, bathed in the glittering acoustics of the space for which it was written — even though it was recorded in a studio in California.