This song is named after Opus 40, a large environmental sculpture located in Saugerties, New York, created by sculptor and quarryman Harvey Fite (1903-1976). Keyboardist Adam Snyder recalled to Uncut in 2015: "I remember Jon (Donahue,vocals) and I were sitting in a room in Kingston, which is like the gateway to the Catskills. I started tinkering around with a Wurlitzer, and that's how 'Opus 40' was born."
Guitarist Sean "Grasshopper" Mackowiak added: "Opus 40 is a place here in the Catskills - Jonathan grew up around here, so that was a place that he used to go to, hang out there in the sculpted rocks of the bluestone. All the bricks of the Empire State Building and most of the Lower East Side came from this brick company that was here in Kingston."
Jonathan Donahue's lyrics quote from Bruce Springsteen ("Woke up and climbed from the suicide machine") and The Doors ("I'm alive," she cried, but I don't know what it means").
This was released as the third single from Deserter's Songs. British music magazine NME named the LP their album of the year for 1998.
Levon Helm was the drummer on this song. His fellow Band member Garth Hudson guested on another Deserter's Songs track, "Hudson Line."