Kara DioGuardi may live on the west coast, but she finds plenty of inspiration in Tennessee. The former 'American Idol' judge is spending time with previous 'AI' champ Carrie Underwood, writing for the superstar's next album. While Kara expects a creative burst in Nashville, nothing will top their last writing session, when the two penned Carrie's last two singles -- 'Undo It' and 'Mama's Song' -- in record time.

"We wrote those two songs in one day," Kara tells Billboard. "It was the craziest session I've ever had. To write two songs in five hours that both charted was ridiculous."

Kara, who joined Simon Cowell and Randy Jackson at the judges table on 'Idol' in 2009, with the addition of TV host Ellen DeGeneres in 2010, says she holds no ill-will towards the hit TV show, even though she was not invited to return this season. "I haven't seen it," she admits. "I'm more interested to see what they do live, and what the talent's like then ... I've been just doing all these other things, but I hear it's going really well, and I'm happy about that. I hope they find a great few people this year."

The 'other things' include a new TV show, a book and a few concerts. Kara will return to the small screen later this year, when she joins Jewel on the songwriting competition, 'Platinum Hit,' on Bravo. Even though she will be reprising her role as judge, she insists that is where the similarities end. "This was taped -- it was a lot more relaxing and you could say a lot more. You didn't have [to say] a 30-second soundbite," she reveals. "I could point out things within the song that they really needed to understand in songwriting, and you could see the improvement the next week, whereas on 'Idol' you couldn't really do that. It was, 'I liked it, I didn't like it.' You couldn't help them pick songs, you couldn't tell them which part of their range to work on, because the audience just wouldn't have understood it or cared."

She also found time last year to write a book, 'A Hell of a High Note,' which will be released April 26. "Every chapter is a song, and it's not exactly telling you about the song but how it came out of my life," she notes. "If the title was [Pink's single] 'Sober,' it doesn't talk only about how the song was written; it talks about my battle with addiction, with an eating disorder ... It's not like a whole chapter on how 'Sober' was written, but at the end it gives a reflection on it."

Kara will return to Music City as a performer only two days after her book is released, when her several-city tour passes through town. During the event, she'll sing some of the tunes she wrote that became major hits, including Ashlee Simpson's 'Pieces of Me' and Enrique Iglesias' 'Taking Chances.' "Over the last few years I did these shows where I sang the hits I had co-written and gave the stories behind them," she explains. "So it's part speaking and singing, and then I sing them in acoustic fashion. They're all stripped and broken down to the way they were written."

The singer-songwriter is currently on the charts with Darius Rucker's Top 20 hit, 'This,' that she wrote with Darius and Frank Rogers. She will also see her songs on several upcoming releases, including projects by Luke Bryan, Colbie Cailat and Jason Derulo. Other stops on her tour include visits in Los Angeles and New York City. More information about her future performances can be found here.