Last night, the 25th anniversary of South Park was celebrated with a concert at Red Rock Amphitheatre in Colorado. Primus, who composed the show’s theme song, and Ween, who have appeared in the cartoon, were both on hand to perform both their own songs and songs that series creators Trey Parker and Matt Stone have written over the years. Ween and Primus played together and separately, and both Parker and Stone came out to play with them.