When Julie Roberts wants to hear some tunes, she gets in her car, drives around Nashville, cranks the radio as high as she can and sings along at the top of her lungs.

"I love to listen to it loud," she says with a signature giggle, "so much so that I've blown my speakers!"

It's an old habit, but also, she says, "an escape for me." Growing up in South Carolina, she would sing along with whatever her mother was listening to. It was good practice for the singer, who today has a deep knowledge of country music as well as a voice that is both commanding and nuanced, powerful yet intimate.

Ten years ago, when Roberts was working as an assistant at Mercury Records, she submitted an anonymous demo, and her voice impressed her bosses, who had no idea it belonged to the young woman who sat just outside their offices. She released two albums on Mercury, her 2004 self-titled debut and 2006's Men & Mascara, and enjoyed a handful of modest hit singles, including "Break Down Here" and "Wake Up Older."

In 2010, however, everything crashed down around Roberts all at once. Mercury declined to release her third album and dropped her from the roster. The Nashville floods gutted her home and destroyed her beloved car stereo (as well as her car). And she revealed she has multiple sclerosis.

"I've grown a lot because of that, and I'm much stronger," she says. "I've lived a lot since then."

That much is clear on her latest record, Good Wine & Bad Decisions, her first for the venerable Sun Records -- the original label home to Elvis Presley, Johnny Cash and Jerry Lee Lewis, among many other rock innovators. When CMT Edge called her to discuss her favorite wine and her favorite Sun songs, Roberts escaped again to her car -- not to sing along with the radio but to get away from her four dogs.

"They bark so much that you'd never hear me if I stayed in the house."

CMT Edge: When you're making a bad decision, what kind of wine do you drink?

Roberts: I love red wine. It doesn't really matter the kind, and it doesn't have to be expensive. If I like the taste of it, that's good wine. But I always find myself choosing a cabernet. When I first started drinking wine, I would go for a merlot or a pinot noir, but as I learned more about them, I shifted to the cab. My mama likes white. I live with her, so sometimes I'll have some of that if she's having it. But most of the time, it's red.

I'm guessing you opened a nice bottle when you signed with Sun Records. Pretty much everybody knows about Sun, but what was your experience with their music?

To me, all of the music on Sun ... nothing sounds alike. Sun was always a rebellious label. Artists did what they wanted -- whether or not they fit in. They made the music that they loved. When I was making this record, I thought, "I'm not going to change who I am. I'm going to make the music that I love and that means something to me."

Nobody came in to give us notes or said we had to change anything. I made the record I wanted to make, and I feel like that's part of Sun's legacy. The artists were definitely artists. They were unique. When Elvis comes on the radio, you know exactly who it is. He had his own style. So did Johnny Cash. So did Roy Orbison.

The album includes "He Made a Woman Out of Me," which is in the Sun catalog. Why did you choose that song?

I wanted to pay tribute to Sun. I told [Sun Records president John Singleton] that I wanted to put a Sun song on my record, so I started going through their huge catalog of about 8,000 songs. Just listening. I love listening to songs. It was a big task, and I didn't get through all of them.

In the middle of all that, John sent me an email that said he knew I was listening to songs, but he had one that might be perfect for me. And it was "He Made a Woman Out of Me." The original recording artist was Rita Remington, although Bobbie Gentry also sang it. It was perfect. I knew then that he really did believe in the artist he had just decided to work with. It's one of my favorite songs on the record. It's so me.

What can you tell me about "Old Habit"?

"Old Habit" is about my mom. She dates a guy she's been seeing ever since she moved to Nashville, but she only went out with him on Saturday nights. That's the only time he ever called her. One Saturday morning, I said, "Mama, are you going out with your friend tonight?" She always called him her friend.

And she said, "I think I'm going to tell him I can't."

"Why not?"

"Because I feel like an old habit. He never calls me any other day of the week. Only Saturdays."

I told her I thought that was a good idea, but I got a song out it. I think I was in her head when I wrote it, and I became her.

What does she think of it?

She loves it. She likes that traditional sound. But if her friend ever comes to a show of mine, I will not tell that story!

Your mother sounds like she was a big influence in your music.

Definitely. She used to listen to a lot of gospel music. She loves Otis Redding and Patsy Cline, soul music and traditional country music. I grew up listening to whatever she had on in the car, and we would sing along together really loud. Today, if I find a good traditional country station on satellite radio, I know every song. My friends are like, "How do you know all these songs?" That's what I grew up with.

You've been holding on to some of these songs for several years now. How do you know when the time is right to record it?

"Keep Me Up All Night" I co-wrote right around the time of my first record and held onto it for a while so it could be pitched around town. I knew I wanted to record it for the right album, but I also didn't want to keep my co-writers from getting a cut. I was so nervous every time another artist would put it on hold. I didn't want to say I was saving that one for myself, but I'm glad it was still there for me when I got ready to make this record.

I've been singing "Gasoline & Matches" for a few years now, but I didn't write it. Buddy Miller did. My fans know that one, and I really connected with it. I love Buddy, so I asked him to sing on it. And he liked how we did it. That made my whole year.

Have any of these songs evolved or revealed new significance to you in the time since you wrote them?

If I love a song and really connect to it, I might connect to it in a different way in a year or in three years. If I write a song like "Keep Me Up All Night" about one person, and I'm dating somebody new three years later, I'm gonna be thinking about the new person when I'm singing it.

To me, a strong lyric never gets old, whether I wrote it or someone else did, like that Steve Earle track on the album, "I'm Not Getting Any Better at Goodbyes." I have songs on my computer that I just can't let go of. I always go back to them, and I'll just wait until the time is right.