One of the great lost sound effects of the New York area was the sound the Brooklyn Bridge used to make before its corrugated metallic roadway was replaced with a standard concrete surface. The bridge generated a constant multi-layered drone that rose and fell according to the speed, number and weight of the cars driving on it. Fortunately, Wendy Mae Chambers recorded the sounds and issued it on a single back in 1982: [download MP3]. Sonic Youth's Lee Ranaldo was also a fan of the Brooklyn Bridge drone and he recorded this tribute to it, which came out on the late great audio cassette magazine, Tellus, Volume 10: [download MP3].
Meanwhile, across the Atlantic, London's Millennium Bridge has temporarily become the world's longest stringed instrument, thanks to Bill Fontana's project, Harmonic Bridge. Fontana applied vibration sensors to the footbridge's suspension and handrail cables so that the movement of people and sheep moving across it are amplified into audible sounds. The page above has MP3 samples and a flash tool that lets you "play" the Millennium Bridge. Thanks Bas! (Photo by Charles Peifer)