No one knows who wrote 'Pipe Dream No. 7.' It exists in dozens of regional variants, each shaped by the specific work environment that adopted it — the maintenance tunnel crews sing it in a slow 6/8 that matches the rhythm of a wrench turning against resistant pipe; the dockworkers' version is faster, syncopated to loading crane cycles; the recycling plant workers in the Shelf's Oku Quarter have a version with an extra verse about the smell of burning insulation that no other variant includes. The earliest documented recording dates to 2188, but workers interviewed in ethnographic surveys consistently describe it as something they learned from someone older, who learned it from someone older still.

Musically, the song is built on a repeating modal phrase of unclear origin — ethnomusicologists have identified structural similarities to Malian griot work traditions, to Norwegian sea shanties, and to a specific rhythmic pattern used in Okinawan agricultural songs, but no single lineage explains it. The lyrics, in all versions, describe the same thing: the psychological landscape of a very long shift, the way time distorts when your body is doing repetitive work, the small negotiations you make with exhaustion, and a final verse about going home that is either deeply hopeful or heartbreaking depending on how it's sung.