Kwerks Dance Machine can now hold up to *99* menu selectable dances with zero lag. Comes with 33 freebie dances but you can drop your own in as well. It functions as a dance ball or a chimera if you wear it. The prim is full mod so you can change it into a floor or drop the scripts in whatever you want.
Check out the listing on SLExchange:
http://slexchange.com/modules.php?name=Marketplace&file=item&ItemID=221913
or visit the lab in Alleni if you want to try it out:
http://slurl.com/secondlife/Alleni/66/190/31/