The park will fit the people but maybe not in the same concentration as the stadium you are picturing. Will that stage fit in the park? maybe, its a big park..
Not sure if you are more interested in the venue or the event
![Confused](https://pics3.city-data.com/forum/images/smilies/confused.gif)
The fete National is one big party that is played out all around the park even if you cant see the stage, a concert in a stadium is more of a show where people come and watch a particular band for a few hours then leave whereas the Fete National goes on most of a day and well into the night and sometimes the whole weekend..