None; just sit back watch. Viewing in full screen is best. :) Note: The animation might be slightly off sync due to variations on how fast Scratch 2.0 operates online on your browser. This is more likely to happen if the project seems to freeze/lag midway, best to avoid have anything huge running while this project is running for best viewing experience. I find that running the animation a second time around improves the sync.
A while ago, I made a project about my YGO/Yami/Yugi/Atem [he needs a Scratch canon name!] plushie dancing (http://scratch.mit.edu/projects/1956556/), but there were only four dance frames I had to work with, since trying to create dance frames in bitmap were hard. With vector, it's easier since I can certain parts and move them around or edit them using nodes. It was also a lot easier to control sync with the new set of "stop" blocks in the 2.0 editor. Music: https://soundcloud.com/junkmusic2012/generic-dance-music Graphics: Scratch Cat, Tera, Gobo from Sprite Library. All other stuff made by me.