Zac Brown Band are hitting the studio to record a new album, and Brown says fans should expect the unexpected.

"We're all continuing to grow up and get better as musicians, and the chemistry as a band continues to deepen," he tells Rolling Stone. "Our boundaries have dissolved and we're going to still do things that are somewhat familiar that people like, but we're also going to stretch out and take chances beyond what we've done before. Some people are going to be really surprised."

The group went into the studio this week to begin the sessions for the new project, which Brown says will last for two-and-a-half months. "We've got 18 strong songs that we've whittled down and gotten ready," he relates. "But you never know; one might pop up and get done right before [we start recording]."

ZBB will release their first-ever hits collection, 'Greatest Hits So Far ...,' on Nov. 11. Brown calls the album "a placeholder" until fans can hear the new studio recordings, which will comprise the group's first full-length studio album since 'Uncaged' in 2012.

"We spent a lot of time getting [the songs] all down and ready to go, so when we go into the studio to record, it's all business," Brown says. "We're not in there necessarily creating; we're in there executing what we've been working on these last few years to create."

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