As women in pink Stetsons and high heels take their seats, Dolly Parton totters on stage in a tight white dress that exaggerates every curve. There is polite pandemonium. Her face and frame may be triumphs of Botox and collagen, but her voice is as pure as mountain air as she launches into a version of Walking on Sunshine. She does a little hoedown, and her enthusiasm is infectious. She would make an excellent primary school teacher. "We need to feel good," she declares, and you think, "Yes, Miss Parton, we do."
The anecdotes are often longer than the songs. And they are all meticulously rehearsed to sound off-the-cuff, such as the one about the red-haired girl who tried to steal her husband that prefaces Jolene.
There is a bluegrass medley, complete with yee-haws and yodelay-heehoos, that includes Dueling Banjos and numerous references to her being a country girl. Parton reminisces about growing up as one of 12 children in poverty in the Tennessee mountains, and it sounds like an episode of The Waltons, so full is it of folksy charm and homespun homilies. She sits on a quilt to tell a story about a coat made for her from scraps by her "Mama" as images appear on the screen of a sepia shack. As her voice cracks, you don't know whether to laugh or cry. When she picks up a shiny saxophone and asks, "How did I get one of these from such humble beginnings?" you think, "Enough of the protestations of poverty!"
Behind the sentiment and shtick, there are dollops of ersatz country – but this is more of a generic US pop-rock sound than it is the real thing. Nevertheless, Parton is a respected songwriter, and pens most of her own material. When she plays tracks from her new album, Better Day, on an acoustic guitar it reminds you that she was a serious musician and ambassador for Americana before she became a figure of cartoon-country fun.
After a 20-minute interval, Parton reappears in a red sequinned jump-suit ("It costs a lot of money to look this cheap," she jokes), and after dispensing with 2001's Little Sparrow, which is as arrestingly solemn and sparse as a traditional folk tune, she cranks out the hits that people have paid to hear. Here You Come Again gets everyone on their feet, and Islands in the Stream keeps them there.
As the singer makes her final assault with I Will Always Love You, infused with country-gospel fervour, and 9 to 5, sung against a glitzy apocalypse of a Las Vegas backdrop, it occurs to you just how strange this self-styled Backwoods Barbie – equal parts Lady Gaga and Loretta Lynn – really is.