While the elevated line had been around for decades by the 1900s, the first underground line of the subway in New York City opened on October 27th, 1904. Singer Billy Murray seized the opportunity and penned a song called "Down in the Subway," which was released on December 2nd of that year, and the audio recording is amongst the archived gems at The Library of Congress. You can listen to the song below—they warn that as with all of their historical recordings, it "may contain offensive or inappropriate language" but we didn't notice any. It does, however, paint the subway as the new "Lover's Lane," and even as a place to escape the ol' ball and chain, with lyrics like: "If married and home is unhappy, you can now hide away from your wife (oh joy), down in the subway." (Ain't that the truth?)

Here's the sheet music—someone please re-record a modern day version! The song was featured in River of Steel, a documentary chronicling how the New York City subway was built. You can hear it around the 1:40 minute mark, when the doc gets into how the subway was celebrated in songs, stories and films.