Sometime during the fall semester of 2018 at Handelshögskolan, or the Stockholm School of Economics (SSE), a red plastic sign mysteriously appeared on the wall of the library’s third story. In white debossed letters, it read: “Absolutely NO saxophones in the library under any circumstances (under penalty of expulsion)”.

Many emails across library staff and school administration later, two things were determined. First, that nobody knew who put it up—or at least, nobody was willing to admit to their secret inexplicable saxophone vendetta. Second, having it up didn’t actually harm anyone, and it may as well remain, to add to the school’s charm. And thus here the sign remains, years later.

After the sign’s appearance, the library staff had their own fun, and put out a notice saying that with the saxophone problem now brought to their attention, they had taken the additional steps of banning accordions, tambourines, and banjos. Since these rules’ enactment, however, they have not been enforced once. No SSE student has to date been expelled for bringing a saxophone into the library. Whether or not it’s just a matter of time before someone becomes the first is yet to be seen.

Although it is a business school, SSE has many different art projects around the building. These include paintings, sculptures, a large chair made out of stone, and an artsy video playing on a large screen in the main room that is rotated out once a month. But the anti-saxophone sign is the school’s only guerrilla art piece, unsanctioned by the school at first but accepted after the fact. Although it seems safe to assume it was probably the work of one or more students playing a joke, it is also the school’s only art piece with unknown origins.