Reese Witherspoon: Singing to bring home the bacon

US actress Reese Witherspoon is "actually excited to play a pig".

Witherspoon, 40, said: "I like pigs. A lot of people I worked with are pigs. I am just kidding."

The Oscar winner, is speaking about her new role as Rosita, a harried pig with 25 piglets in the new animated musical Sing.

She wants to change her family's fortunes by entering a singing competition at an old theatre run by an optimistic koala, Buster Moon (voiced by Matthew McConaughey).

Sing has more than 65 songs, from current pop to old favourites, Drake to Frank Sinatra.

It opens here tomorrow and also features the voices of Scarlett Johansson, Seth MacFarlane, Taron Egerton and John C. Reilly.

Tell us about Rosita.

I liked the idea of playing this mum who has so many children (that) she has given up a lot of her dreams. But she still has this one dream inside of her, and she can't let it go. I think a lot of people can relate to that.

Are you close to McConaughey?

Yeah. We are very good family friends. My husband (talent agent Jim Toth) represents Matthew. He has been his agent for many years. So I know Matthew and his children very well.

They were at my wedding and I was at theirs. We are both from the south, so we kind of get our southern accents on. He is a great guy with a lovely family and very grateful about his life.

Did you ever want to be a singer?

When I was a little girl, I wanted to be a country singer. Dolly Parton, to be specific. So I trained to be one, which never happened, except in one movie, Walk The Line, in 2005.

So it's always fun to go back to that. But then I hear people like (singers) Tori Kelly and Jennifer Hudson and I am like yeah, I will just stick to acting (laughs).

Do you sing at home?

Yeah, I am always dancing and embarrassing my children.

I like to dance to Rihanna. Drake is a new favourite. One Dance by Drake, that's my new song. My kids are really embarrassed that I know all the words (laughs). But it's fun.

I grew up in a house where my mum was always singing and dancing and being goofy and laughing. I think it adds a kind of lightness to the house.

Do you ever feel as harried as Rosita?

Yeah. I have three kids in three different schools. And then Los Angeles, that's really hard because of all the driving. It's a lot of coordinating too, as I have two teenagers and a toddler.

But I do think maybe one day, they will have to drive me, which will be nice. Now that (my oldest daughter) Ava can drive, I am like, you drive, I don't want to drive any more.

I am sick of driving (laughs).

How do you make time for yourself?

It's a hard balance as a mum. You want to give your whole self to your kids. You take the clothes off your back when they are cold, you take the food out of your mouth if they are hungry, and you lose all sleep for years. I haven't slept since Ava was born 16 years ago (laughs).

But it's important to create things for yourself, and my work is very personal to me. My kids know that is a really important part of my life, and part of being an artist is you have to create a space that is best for yourself.