AUSTIN, Texas - The Jonas Brothers are nearing completion of their fourth album, due out June 15, which the trio says will take the band in new sonic directions.

"This album is taking steps," Nick Jonas told Billboard.com during a teleconference with reporters on Wednesday. "We're trying to learn as much as we can, continuing to grow."

Kevin Jonas said, "The overall message is it's the same old Jonas Brothers, in a sense," but he noted that the group would be adding more instrumentation, including horns and strings "to add and build to the sound we already have."

Nick said the songs on the new album -- whose title the brothers are not yet revealing -- are "our journal in songs," mostly about "all things we've gone through, personal experiences we get inspiration from." But citing the continuing influence of Elvis Costello, he added that "we've also been working on trying to use metaphors ... to kind of mask a literal thing that happens to us."

Other inspirations the trio cited for the new album include the Zutons, Kings of Leon and Neil Diamond.

Nick said the group already has recorded nine songs with "a few more to go." John Fields is again producing the album, which was recorded concurrently with the filming of the trio's new "J.O.N.A.S." action/adventure/comedy series, which will debut in May on the Disney Channel. Several songs from the album will be featured in the show as well.

The Jonases are also gearing up for their first world tour, which begins June 20. The show will be performed in the round on a 144-foot-wide stage that incorporates a large circular water screen.

"We wanted to find a way to provide a bigger and better show to our fans," Joe Jonas said. "The entire bottom half of the arena and the upper desk is essentially a front-row ticket."