That's when Parton, 68, pulled out a small, bejeweled saxophone and played "Yakety Sax," the iconic theme song from British comedy's The Benny Hill Show.
"I wanted to do something to impress you. So I put the stones all over this, let me see if I can do the rest," she said.
Parton told reporters before her performance that the chance to play Glastonbury made her "feel like a rock star."
"I saw all the tents and the people, and I can't believe after all these years I've never done Glastonbury before," she said. "I'm so excited to be part of this whole thing. I'm just a country girl and now I feel like a rock star."