»In which the hum is coming from her

The American composer Joseph Bertolozzi is composing a "Bridge Suite" with sounds sampled from the Mid-Hudson Bridge, described in this article from The New York Times:

The purpose of the test was to check not the bridge’s soundness but its sound. The rather bizarre scene on the Franklin D. Roosevelt Mid-Hudson Bridge near Poughkeepsie was part of Mr. [Joseph] Bertolozzi’s audacious plan to transform the span into an orchestra, compose a piece for it, then actually perform the work live with a small army of percussionists. It is a musical undertaking on a vast scale and one that has brought oddly harmonious marriages among the worlds of art and government, music and engineering.

Mr. Bertolozzi, 48, has been meticulously harvesting a multitude of sounds from the structure: not just the cables, which on playback create woo-wooing effects or sounds like a bass guitar, but the spindles below guardrails, the rails themselves, the interior and flanges of innumerable I-beams, connecting metal plates and the grates between walkways.

He sent mounds of steel pellets down the interior of a 315-foot steel tower to create a rain-stick effect. He collected clanks from the “Hudson River Estuary” sign, with its blue sturgeon emblem. An organist as well as a composer, Mr. Bertolozzi even hopes to turn large upright conduits for power lines into rough organ pipes.

“I only play big instruments,” he said.