Josh Groban openly admits he isn’t the same performer that his fans saw when he last toured in 2007.

“I think that anybody who just starts out and is handed a huge tour usually kind of falls into the trap of performing at an audience rather than with them,” Groban said in a phone interview. “In the past, I’ve worked meticulously at rehearsing a show that, regardless of what the crowd’s intention felt like, that was going to be the show.”

Groban knew he wanted to create more of a spontaneous exchange between himself and his audience for his next tour. And before he put together this year’s “Straight To You” tour of arenas, he played a series of small venue concerts where he performed solo on piano in a show designed to force him to relate and respond to the audience.

“My manager’s idea was go out on stage, have about 30 songs rehearsed, but don’t know which 15 you’re going to do,” Groban said. “Just go out and enjoy the audience. Take questions, talk about the songs and whatever happens happens. Fill 90 minutes.

“I thought ‘Are you nuts? This is how people die on stage.' And it was the fastest moving 90 minutes I’ve ever had and it was the most fun I’ve ever had on stage.”

To help bring that spontaneity to arenas, Groban and his team have structured his new show to be less rigid and more spontaneous.

“I feel very excited about expecting the unexpected,” Groban said. “Some songs that I know I’m going to do every night, I have great visuals for and we have great moments that we know we want to pinpoint during the show. At the same time, there are a lot of open gaps where I think ... anybody who’s been to those smaller shows, [they know]  there’s going to be a lot of interaction. And I think it’s a wonderful feeling to be a little scared and excited at the same time before you go on.”

It’s not just Groban’s approach to performing that has evolved since his 2007 release “Awake.” He’s made major changes with the studio side of his work as well.

Now 30, Groban decided to change producers, temporarily setting aside his partnership with producer David Foster that resulted in three platinum-plus-selling studio CDs – 2001’s self-titled CD, 2003’s “Closer” and “2007’s “Awake,” topped off by his 2007 Christmas CD, “Noel,” which has sold more than 5 million copies.

“We felt like we needed to take a rest and get fresh again and miss each other,” Groban said.

For Groban's 2010 release "Illuminations," he surprised observers by partnering with producer Rick Rubin, the mega-producer known for his work with Metallica, the Beastie Boys, Johnny Cash and Neil Diamond, to name a few.

Groban knew working with Rubin was a gamble, but he saw potential for something exciting.

"[Rubin] took things out of my tool shed that kind of made me flinch at first, like drums, for instance, or electronic instruments," said Groban. "I’ve always been a big electronic music fan. I'm a big computer music fan. And he really wanted to have this record to not sound like it had a date stamped on it. He wanted it to sound like it could have been recorded 50 years ago or 50 years from now. I appreciated that.”

Rubin also pushed Groban to write more new songs for "Illuminations" than he has for past CDs. In the end, Groban co-wrote 11 of the CD’s 13 songs, working on many tunes with Dan Wilson from the rock-pop groups Semisonic and Trip Shakespeare.

Groban credited Rubin for helping his songwriting.

“I think anybody who writes will say it’s about a creative environment, putting yourself in a space where your head feels like it’s successful for ideas,” he said. “And Rick is a great guy at creating that environment. So the ideas just kept coming and I was very lucky for that.”

Despite the changes, “Illuminations” still sounds very much like Groban, much to his fans' content. No matter how much he tinkers with the stage show or challenges himself in the studio, his sound is still rooted in soaring, cultured vocals, classical instrumentation and anthemic pop.

Concert preview

Josh Groban

7:30 p.m., June 8; $98-$78

Arena at Gwinnett Center, 6400 Sugarloaf Pkwy., Duluth 770-813-7600, www.gwinnettcenter.com