Why the Golden Gate Bridge now 'sings': San Franciscans post audio of 'whistling, melodic tones' reverberating through city as 60mph winds sweep through bridge's new sidewalk railings (10 Pics)

San Francisco residents were serenaded by the iconic Golden Gate Bridge on Friday as the high winds passed through a new installation on the overpass and released melodic tones that echoed through the city.

Social media users shared videos revealing an eerie and at times angelic humming sound emitting from the bridge, with some claiming they could hear the strange noise from miles away.

The Golden Gate Bridge Sargent explained that the phenomena was the howl of high winds passing through a recently installed sidewalk railing featuring vertical slats on the bridge. 

The new slats were intended to help with wind resistance and are thinner than the ones the bridge had prior, allowing more air to pass through. But as air rushes through at high speeds, it emits a sound not so different than that of a wind instrument. 

On Friday powerful wind gusts of 45 to 60 miles per hour were reported in San Francisco and Marin counties.

San Francisco residents were serenaded by the iconic Golden Gate Bridge on Friday as the high winds passed through a new installation on the overpass and released melodic tones that echoed through the city

The Golden Gate Bridge Sargent explained that the phenomena was the howl of high winds passing through a recently installed sidewalk railing featuring vertical slats on the bridge

Initially bridge officials said they did not know that under extreme conditions, the air rushing through the slats would release the loud tones, but later walked back on their comments and said they did know the bridge would create the sounds.

'We knew going into the handrail replacement that the Bridge would sing during exceptionally high winds from the west, as we saw yesterday,' Golden Gate Bridge, Highway and Transportation District spokesman Paolo Cosulich-Schwartz said to ABC. 

During design, the district studied the potential impacts of the project, including wind tunnel testing of a scale model of the bridge under high winds.

The tests revealed that under certain high wind conditions, the bridge would hum as air passed more freely over the Bridge roadway.

'This is part of the wind retrofit project, where we have replaced much of the westside hand rail so that the bridge can be more resilient to really high wind,' Paolo Cosulich-Schwartz with the Golden Gate Bridge District explained to CBS.

'The slats on the new hand rail are much thinner than the old hand rail which means that air can flow more freely across the bridge.' 

Social media users shared videos of the unique music the bridge sang over the city on Friday during powerful wind gusts of 45 to 60 miles per hour

This Twitter user said that when passing over the bridge's sidewalk it hurts the ears to hear the strong wind tones

This Twitter user shared video from Presidio asking what the eerie sound reverberating in the area was, not knowing it came from the bridge 

Clueless locals shared videos on Twitter and Facebook of the singing 83-year-old suspension bridge, asking for an explanation. 

'Can someone explain to me why is this eerie sound has been going on for an hour in San Francisco,' one baffled resident tweeted in Presidio.

'Here’s the sound from Land’s End I had been hearing it for weeks and felt like I was losing my mind,' another added.

'The Golden Gate Bridge now makes music. You can hear this whistle all over the city,' one Twitter user wrote.  

While the music seemed lovely from afar, for bikers and pedestrians on the bridge itself, the tones were disturbingly loud.

'Engineers designed new sides for the sidewalk to help with wind resistance but didn’t take into account the EXTREME sound it creates when wind passes through it. The bridge sings crazy songs now it’s so trippy. It hurts the ears and unbearable it’s that loud,' one Twitter user complained.

'I couldn’t really describe the sound. I think I described it as wind chimes at first and, then, like when you blow into a beer bottle. But then, like multiple beer bottles, because it’s different tones,' Brianne Howell described. 

The rail replacement is about 75 percent complete so the noise could get louder under the extreme wind conditions. 

However, the district has no plans to change plans on the project.