Because there were so many visitors (and because they had to earn more money to pay for the high price of the main act), the organizers decided to have the same program again on a second day. It was the first time in the festival's history that they organized a two-day event. Usually the event lasted for one day only.

Careful: Actor and act is not the same thing. I think they are referring to musicians here, not actors. If you use 'artists' you will be on the safe side.