You might've heard of the concept of a "bridge" in music. Well, guitarist Nate Mercereau is taking that term literally. In July, he released a new album in collaboration with San Francisco's Golden Gate Bridge — yes, you read that right — titled Duets / Golden Gate Bridge, which features droning guitar improvisations over the eerie hum of the Bay Area landmark.

Mercereau says he first heard about the sound through a San Francisco Chronicle article that delved into how residents have been complaining about it. But when Mercereau heard recordings of the sound, which is produced by wind passing through the slats of the bridge, he was immediately struck by its beauty.

"It's remarkably musical," Mercereau says. "It plays multiple notes."

In May, Mercereau — who's worked as a session musician with Jay-Z, Leon Bridges and more — alongside engineer Zach Parkes and photographer Minea Bisset trekked down to the Marin Headlands by the bridge and spent two days recording duets with its hum. Mercereau weaves low, slow melodies around the bridge's ominous tones, which he likens to Tibetan singing bowls. Listen to him describe the process and meaning behind Duets in the audio player above.

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