Dolly Parton is less a singer, more a one-woman world-domination machine.
You'll most likely know her as a singer, though. You may have seen her in the odd film or two, and you might know she owns her own theme park - called Dollywood, naturally.
On top of this, she's also a published author with several autobiographies, works of fiction and cookbooks to her name, including the brilliantly titled Dolly's Dixie Fixin's: Love, Laughter And Lots Of Good Food. She also co-founded Sandollar Productions with her former manager Sandy Gallin (if you're a fan of Buffy, you owe them a debt of gratitude for turning the high school vampire slayer into a TV series).
She's sold more than 100-million records worldwide, but perhaps even more impressive is Dolly Parton's Imagination Library, the charity she founded to distribute free books to disadvantaged pre-school children across the US - the fund currently sends out around 8.3-million books a year.
"I'm sure keeping very busy," she says, after reeling off all the different engagements and meetings she has in her schedule, before countering it with a typically upbeat sentiment.
"I've dreamed myself into a corner, and now I have to be responsible for all of it," she says, the definition of chipper. "Whenever duty calls, I run."
Dolly Parton doesn't do whingeing, at least not publicly. At 68, she embodies the same girlish charm and bubbly persona as three decades ago.
After a few years tending to the rest of her empire, she's spent 2014 so far touring the world, playing in the States in January, before travelling to Australia and New Zealand, promoting her new album Blue Smoke. It's released in the UK this month, shortly before she begins her arena tour and performs at Glastonbury.
"I've had a wonderful time playing this year, the crowds have been good each night, and I'm very excited for the UK shows. We haven't been for three years or so, and we had such a great time then. I just want to recreate that."
Blue Smoke, then, is Parton's 42nd studio album and comes a full 47 years after her debut, 1967's Hello, I'm Dolly.
"Blue Smoke is the name of the first song on the album too. It's about a heartbreak train called Blue Smoke," she says, adding that she got the name from the Great Smoky Mountains which she grew up in the shadow of. "The Cherokee call them Shaconage, which means 'land of blue smoke', which seemed perfect for me."
The titular song finds Parton singing close Appalachian harmonies with her band, while a lap steel guitar and violin play on in the background. It sounds like the definition of country music.
Elsewhere on the album, there's a duet with Kenny Rogers called You Can't Make Old Friends. It doesn't reach the heights of their most famous singing partnership, Islands In The Stream, but then few songs do.
"It's one of my favourite songs we've ever sung together," explains Parton. "It's a very emotional song, because it's so true. We're great friends and have been for such a long time, and we've had a great time singing together over the years.
"Islands In The Stream is over 30 years old now, believe it or not. We've recorded other songs through the years too, but You Can't Make Old Friends is very special. It speaks of true friendship and a lot of people will be able to relate to it. You can always meet new people and make acquaintances, but nothing is like having an old friend that you share memories with."
Among the tracks Parton wrote specifically for Blue Smoke is Unlikely Angel, which she first sang in a little-seen TV movie around 14 years ago. As she was always very proud of the song, she decided to give it another lease of life.
There are also a couple of covers; firstly Bob Dylan's Don't Think Twice, It's All Right, which she says she often sat around her house singing anyway, so thought it time to finally record a version, and perhaps more surprising is a cover of Bon Jovi's Lay Your Hands On Me.
"The first time I heard it, years ago, I was sure it was a gospel song. But then I got around to covering it and realised that no, it's not a gospel song, it means something quite different, but it should be and it could be a gospel song. It's one of my favourite songs on the album."
Finally, Bands Of The Ohio, is a new arrangement of a traditional folk song.
"It's a few hundred years old, and it's always been a man's song, even though Olivia Newton-John recorded it some time ago," says Parton. "I always wanted to record it since I was a little kid, but I needed a reason to do so, so I presented myself as a writer or journalist going into prison to interview the central guy in the song. So hopefully it's given me and other girls down the line an easy way to record it and make it a girls' song too."
With that, talk turns to Glastonbury. Parton has been booked to play the so-called 'Legend' slot on the festival's Sunday afternoon.
"I will try to bring some Nashville weather with me," she says. "I can't wait, though. I've played to that many people before - years ago with Linda Ronstadt and the Eagles - but never something as big as Glastonbury. And never on my own.
"I think I will be a little bit scared," she adds. "Well maybe not scared, but definitely nervous.
"But whatever the weather, or if I'm nervous, we're going to put on the best show. No matter what."
Blue Smoke is out now. Dolly Parton will perform at the 02 Arena, Peninsula Square, SE10 on June 27.
Details: 020 8463 2000, theo2.co.uk