You can make your experience as much of a performance as you want :)
This article is a pretty good description.
This summary of 2012 is beautiful.
But no matter how much people try to describe it, it's different every time and for every one. All I can say, it's worth going at least once :)
Generally speaking though - you don't have to make a big art project, or even a small one, but the spirit of the thing kind of inspires people to share things - be it playing live music, or telling stories, or passing out candy, or bringing a truck full of alcohol and setting up a free bar in the middle of the desert, or riding around on a bicycle with an ice-cooler full of watermelons and sharing them with thirsty strangers, or teaching tango, or setting up a stage and holding a professional ballet performance, or anything at all really. People tend to want to share what they love.