The Californian band will headline the festival, which takes place at Strathallan Castle in Perthshire, later tonight.
As Bugg’s set entered its final throes, the Nottingham singer/songwriter told the crowd: “We’re gonna get one of the Red Hot Chili Peppers out here, wherever he is.”
As Smith strode on stage, Bugg continued: “Here he is, Chad Smith.”
The pair shook hands as Smith settled down behind the drum kit and joined Bugg and his band for ‘Slumville Sunrise’.
As the song came to a close, Bugg acknowledged the drummer’s contribution in his typically understated way, saying only “Chad Smith everyone” as the Chili Pepper put his leather jacket back on and left the stage.