For the most part, you will need to purchase festival tickets ahead of time. This is for two reasons. The first is that most good music festivals sell out long before the day they open their gates to the public. The second is that for many modern music festivals, only digital tickets exist. You’re going to need to make sure you book ahead of time. Showing up on the day is likely going to lead to disappointment. If you want to get last minute tickets, the best way might be trying to find someone who is looking to sell their own.