More specifically, it started out in the middle of the 19th century among the students at the University of Uppsala. A spex, however, is not just a farce. The storyline is more or less taken from history. History is re-interpreted in a creative way to suit the purpose of the play, which is to make fun of it. Mostly, it also makes fun of the present by numerous allusions and anachronisms.
Music is an integral part of the performance.
Almost invariably, new words are put to existing tunes. Both classical and modern music is used. Requests for brief replays of what you just saw are also permitted and should be granted. The script is often in rhyme. Puns and more or less silly jokes are abundant.