"If the category sounds a little weird... The Guinness website features such idiosyncratic categories as: Longest singing marathon (by an individual): 105 hours."
This is a singing group — documented on this blog a few times — that assembles, sings for a while, then goes home, and comes back again another time. That's nothing like one person singing for 105 hours. That's just a singing group that meets regularly. I'll bet there's a singing group somewhere that has met regularly for half a century. The SS only go back to the Wisconsin protests of 2011.
This group is hungry for publicity, seeking publicity for applying to Guinness with a ludicrous proposal of a new category consisting of the particular thing that they have done and plumping up the category name with a silly misuse of the word "continuously."
The (unlinkable) OED defines "continuous" to mean "Characterized by continuity; extending in space without interruption of substance; having no interstices or breaks; having its parts in immediate connection; connected, unbroken."
ADDED: Here's my video from March 14, 2011, showing the singers, with shots of the songbook and real-time critique by me.
As I said at the time, this was "edited to heighten the absurdity of appropriating the civil rights song 'We Shall Overcome' (about not being free) and that 'Stickin' to the Union' song (about facing union-busting violence). ... The protests have been on behalf of well-paid people with excellent jobs — better jobs than the average Wisconsinite's.... I know they have their complaints, but they are not even the bottom sector of the Wisconsin economy."