Dolly Parton is having trouble with her headset microphone, beset by a curious knocking sound. "Perhaps it's my brain," she suggests, puzzled. There's always the chance that it's someone signalling her to get on with it. Onstage, her introductory monologues can last longer than her songs: her patter is frequently so corny it could be slathered in hot butter and served as a side at her restaurant chain, Dolly Parton's Dixie Stampede.
Occasionally, it is a little confusing. "I got a bunch of Elton John's friends here tonight," she announces at one juncture. Whether this refers to actual pals of the great man or is merely a tactful euphemism for gay men in general remains unanswered. There's certainly plenty of the latter here, forming a curious alliance with middle-aged suburbanites. If they are looking for camp spectacle, they are not going home disappointed.
You do not expect decorous good taste from a woman with her own theme park, but even the most ravenous kitschophile might draw the line at performing a song lamenting Elvis's death as a duet with a deeply unconvincing Elvis impersonator. Not so Parton, who also has a microphone between her famous bosoms equipped with an echo. "Hello hello hello!" she yells into it. "Talk about the Grand Canyon!"
But despite the wilful tackiness and glutinous sentimentality, it is impossible to dismiss Dolly Parton as a mere purveyor of schlock. She is a fantastic multi-instrumentalist, switching from piano to lap steel guitar to autoharp to fiddle to banjo (indeed, it appears she can play pretty much anything as long as it is coated in six inches of glitter), while her voice, a husky, imploring quaver, is remarkable. She somehow manages to conjure vulnerability even while belting it out with a forcefulness and volume that would terrify Ian Paisley. This makes it all the more unfortunate that she keeps abandoning singing mid-verse in favour of speaking her lyrics in a stagey sing-song voice.
When she stops hamming it up, her skills as a songwriter are self-evident. Jolene is as unimpeachable as ever; The Grass Is Blue a gorgeous, heartbroken lament. Stripped down to just her voice and an ominous synthesiser drone, Little Sparrow sounds astonishing, its roots in English folk music clearly audible. You cannot help wishing there was a bit more of that and a bit less rehearsed chat. But as it ends to a wave of stunned applause, another monologue begins.
· At Newcastle Arena (0870 707 8000) tonight, then touring