Anyone who has had the chance to visit New York’s One World Trade Center site knows that it’s a moving experience. The structure itself is impressive, climbing high into the sky and dominating the already iconic Big Apple skyline. Adjacent to the building is the 9/11 memorial, a solemn reminder of the tragedy that occurred on September 11, 2001 and February 26, 1993, along with the names of the nearly 3,000 terrorist attack victims. Well, as if the site weren’t already haunting enough, a YouTube video posted last week adds a new wrinkle to One World Trade Center’s mystique: When hit properly, the building appears to “sing,” or “wail” in the wind.

Viewers are advised to turn their volume up or use headphones, as the sound is subtle (yet distinctly creepy). Some have likened the tone to a singing chorus, or an eerie Gregorian chant. The uploader provides no details as to when or exactly where the phenomena was first noticed, but the video is here for viewers to see (and hear) for themselves.