Music? The first four days will be safety announcements. The last four will be debates as to who is responsable for cleaning up all the vomit. A week of near-zero-g in a room with 30 people will not be fun.
Why would it be "zero-g" you're not in orbit?
It is possible to crack a joke here and get it upvoted, but it's hard to pull it off. I even once had a joke upvoted by quite a lot,* like 50 points or something, but most jokes are downvoted not because humor is forbidden, but because insubstantive comments are discouraged.
Some humor is downvoted for being uncivil because a lot of humor is basically poking fun at people or mocking them. A lot of humor is not nice at all. HN tries to meet a very high bar for civility.
* Under my old handle and it hit 59 points:
At any rate, way better than "harumph! HN hates fun!"
It’s just a culture thing. HN tends to be more news and factually focused than reddit/Twitter/etc. People here just prefer to stay on topic, especially since humor is very different between people and can be very hit or miss.