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.
Improvisation is more of a rule than an exception.
Some, many or all female roles are played by male actors. In the mid-1800's, there were no female students, so any female characters simply had to be played by men. This tradition lives on, mostly because it is often funnier that way. There are quite a few universities in Sweden, large and small, old and new. At most every single one of these it seems like there are always quite a few students feeling bored or deprived of culture, yearning for self-expression, or perhaps being just a bit crazy.