Higgins is hitting the road to promote her new album and book, both titled Oz, with a gruelling 25 shows in just over a month, throughout the country.

"I recorded the album and wrote most of the book before I got pregnant so it wasn't really planned this way," she says.

"I guess I could've just not toured the album and released it all and just stayed at home and gotten fat, but I dunno – I love being out on the road and I love performing."

She is due to give birth to her and fiance Dan Lee's first child, a boy, in early January. But until then, her most recent creation and labour of love is Oz – an album of covers of some of Higgins' favourite Australian songs, plus a corresponding book of essays, all penned by Higgins.

Higgins first had the idea for a covers album four years ago, when it came time to write a new album.

"I was feeling really creatively blocked at the time and I wasn't inspired to write my own songs and my manager suggested trying a new project," she says.

"I've always loved singing cover songs, especially Australian cover songs. So I figured why not do an album of those covers? I thought it was a great idea in theory but I really, really wanted to prove to myself that I could write songs and that I wasn't completely permanently blocked."

Instead, she wrote her third album, The Ol' Razzle Dazzle, which went to No.1 on the Australian charts, just like her two other albums before it.

But this time around, Higgins felt the time was right to bring the covers album idea to life.

"I wasn't feeling creatively blocked as much and I just thought it'd be fun to go down a different avenue and try something else creatively," she says.

"I mean there's still so much room for creativity in cover songs, especially if you completely deconstruct them and reinvent them, which I've really tried to do on this album. It was a really fun process and really different for me, which I wanted – I wanted something fresh."

The result is 15 Australian songs, re-imagined by Higgins, from a diverse set of artists including Paul Kelly, The Drones, Something For Kate, Slim Dusty and The Angels.

For Higgins, it's the music that inspired her when she was growing up.

"I listen to a lot of The Waifs, Kasey Chambers, Paul Kelly, Something For Kate – there was a lot of Australian music that I was really into when I was a teenager developing my own sound. In a way this album's a bit of a tribute to all the pieces that make up who I am today as a songwriter," she says.

Around the same time that she was getting ready for the album, and doing a lot of research listening to Australian music, Higgins got approached by a publisher, who proposed that she write a memoir.

"I was very flattered to be approached, because she'd read a bit of my writing which I'd submitted for a few literary events across Melbourne, and I considered it for a while," she says.

"But I thought – I still feel a bit young to write a memoir, and I still feel like I'm in the middle of this career – I don't feel like I'm kind of out the other end yet, able to get enough perspective on it, which I feel I'd like to ideally be when I do write an autobiography one day."

Keeping along the autobiographical vein, Higgins thought up the idea of a series of essays, corresponding with the album, to be released at the same time.

"I did think it would be fun to mix it up a bit – write a bit about the process of creating music and my inspiration behind the songs as well as memories from my adolescence – growing up singing and my brother's jazz band and going to my first New Year's Eve rave at 16 and thinking that the Y2K Millennium bug was about to destroy the world – just funny little anecdotes like that mixed in with more poetic stuff," she says.

And Oz, the book, is exactly that: a mixed bag of stories using each of the recordings as the starting point.

"I basically used each song as a springboard to talk about kind of whatever the song inspired in me. Whether it be a memory in seeing that artist play for the first time or what it reminds me of in my own life or in my own upbringing," she says.

"I just thought it would be fun for people to be able to take home this nice book with writing and drawings and nice photos, bound like a proper book. And it would enable them to get a greater experience of the album."

Keeping with the Aussie theme, Higgins called on some of her musician friends to help out and feature on the album.

"Dan Sultan came in and sang a duet with me on the Slim Dusty song, and Kate Miller-Heidke came in to sing on a Blackeyed Susans song, and there's a couple of others," she says.

"I had various musician and singer friends from around Melbourne pop in and play things on the album. So it was a really fun atmosphere."

To add an extra Aussie dose to the album, it's Higgins first album recorded in her home country.

"Before, I was signed to an American record label, so they were offering to pay for it if I did it over there. But I'm not with a major label over there anymore, so it made sense to do it here," she says.

"It was really lovely to come home to my own bed every night and just call up friends to come into the studio at last minute's notice."

So while many sleepless nights are no doubt in order come January, Higgins says she's excited to tour the country, and release Oz - the album and the book - to the world.

"I'd much rather tour this album than not at all because it's always really fun to go out and play new material and rehearse up a new band," she says.

"It's all the stuff I love, playing fresh music and playing songs my fans haven't heard before. It'll probably be my last chance to tour for a little while so I figure I should probably do it now while I can."

Missy Higgins will play at Canberra Theatre Centre on October 11 with special guest Dustin Tebbutt. Visit canberratheatrecentre.com.au for tickets.