The 10,000 Maniacs debut their new look and sound Sunday, at the Fox Theatre. Lead singer Natalie Merchant says impulse and fear triggered changes by the thinking fan's pop-rock band.

"When we got back together after a year off, we decided that we shouldn't be afraid of being different," Ms. Merchant said from Los Angeles. "We're kind of an impulsive band, anyway that's how we decided to take a year off."

The results are intriguing music and image-laden lyrics on Our Time in Eden, which debuted at No. 36 on Billboard's pop chart, and an expanded stage show. The tour-opening Atlanta concert will feature five backup performers, and what Ms. Merchant calls "a great looking set and a couple of surprises that I don't want to give away."

The changes began with Ms. Merchant's decision to share songwriting duties with the four other Maniacs after years of writing in virtual isolation. Then came the urge to use the funky James Brown Homs, a string quartet and a variety of new instruments, including bassoon, banjo, accordion and sitar.

Ms. Merchant isn't certain how long the band, formed in Jamestown, N.Y., near Buffalo, will remain on the road. All the Maniacs have made major personal changes since their last release in 1989, and Ms. Merchant, who lives alone in New York City, became a volunteer worker at a children's shelter.