Not a jest, but a jest-adjacent tale (of unknown height) from a discussion about the London Tube:

When I was living in central London in the mid 80s I had several acquaintances studying music at the RCM*. They fairly regularly used to organise circle line parties wherein members of a band, or musical ensemble, depending on the genre, would loiter at successive stations on the circle line with their instruments waiting for the train with their gathering of friends & band mates to appear. After 30 mins or so one carriage would be in full swing & if they weren't causing a nuisance / looking likely to damage or defile anything (always a risk with music students) & the service wasn't too busy the staff would usually leave them to it for at least a lap or two.

* Royal College of Music