Rob Thomas on Next Album, Solo Tour & Matchbox Twenty: 'Unless Somebody Knows Something I Don't, We're Still a Band'

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Rob Thomas performs at the 6th Annual African Children's Choir Changemakers Gala at City Winery on Nov. 20, 2014 in New York City.

Rob Thomas had every intention of having his third solo album, The Great Unknown, ready and out for his Great Unknown 2015 tour, which gets under way June 11. But it hasn't worked out that way -- though he has released a single, "Trust You."

"A long time ago I just picked a date and said, 'I'm going to be on the road, and if I'm not on the road at this point I'm going to kill myself,'" Thomas said during a recent conference call with reporters to promote the tour. I set a date to be on the road and then moved everything up. The idea now is to be out touring for this single to build up all the excitement for the [album], and then I can do all the traditional promo after that. That's one of the reasons why for this summer we picked more of a theater tour instead of doing the outdoor sheds and keep it in that vibe of, 'We're building something.'"

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The album is largely built, however. "It's done with the exception of one song," Thomas told Billboard. "There's one ballad that I wrote last minute. … It's just my vocal, a piano and a string section, and that's it. If I had to put [the album] out now, I would be proud of it. But I felt like it was missing that one really quiet moment, and I think that might be it."

The Great Unknown, Thomas' first solo album since 2009's Cradlesong, is now expected out during the fall and was executive-produced by longtime collaborator Matt Serletic. But this time, Thomas branched out to work with other producers and co-writers, including Ryan Tedder on "Trust You" -- which Thomas said is about "that one friend you're gonna go out and make a lot of bad decisions with" -- Ricky "Wallpaper" Reed, Dr. Luke cohort Cirkut and the team of Shep Goodman and Aaron Accetta. "Over a quarter of the record, I actually worked with other artists, which I've never really done for me," Thomas said. "I've always done it for their project. Getting to work with people like Ryan and Wallpaper, I think it helped me keep things fresh and not feel like I'm going back to the same well and just writing the same songs over and over and over -- which, after 20 years, that's your biggest fear." Thomas described the album as diverse -- and added that it may also be "the last pop record I ever make."

"I come from so many different places," he explained. "I do know that I've got a Ryan Adams/David Gray record in me. I've done '90s 'I'm angry and I don't know why' alternative. I've done 'I'm going to make you shake your ass' pop. I think if I could hit a real solid 'cry in your beer,' then I'm done."

The Great Unknown tour will wrap up August 13 in Englewood, N.J., and Thomas is planning more legs to follow the album's release. The cycle will likely stretch into 2016, but next year is also targeted for more work with matchbox twenty.

"Unless somebody knows something I don't, we're still a band," Thomas said. "We have our 20th anniversary of our first record [Yourself or Someone Like You] next year, so I know that we're going to do something there and we'll definitely always go out and tour and make music. We have too much fun not to."