Greeting the 2,000 strong gathering with a hearty "Hello everybody", she was slightly taken aback when a girl in the front seats replied: "Hello, miss."
Dunbar did indeed adopt the persona of the sexually repressed schoolmarm with the strangulated tones from her television show, during which she made prolonged use of the word "precipitation".
Eventually, she plucked up courage and reverted to the vernacular: "OK, it was pishin' doon."
Predictably this produced the biggest laugh of her performance and prompted her to comment: "Ninety-five per cent of you enjoyed that and the other 5 per cent are wondering why they booked me to do this." Quite.