Aaron and Ryan Garber figure it's not every day that identical twin composers premiere new works together. But that's what they'll do Saturday at 8 p.m. in Jefferson Center's Shaftman Performance Hall.

"We've worked on some things together before," Ryan Garber said last week, "but nothing of this magnitude."

The concert will feature a full orchestra, the Salem Choral Society and soloists Marianne Sandborg and Powell Leitch. It will mark the debut of Aaron Garber's "Mass for Peace" - a musical setting of the Catholic Mass interspersed with a contemporary poem for peace - and Ryan Garber's Concerto for Piano and Orchestra, which will be performed by Aaron's wife,Melia.

"She's a phenomenal pianist. Phenomenal," Sandborg said. "She just has so much soul in her playing."

Among the Garber boys' identical traits was a love of music - but it led them to different careers. Aaron is director of church music at College Lutheran Church in Salem and leads the Salem Choral Society; Ryan is assistant professor of music at Carson-Newman College in Tennessee.

Ryan holds a doctorate in composition and Aaron has a master's degree in choral conducting, and both have written numerous pieces for performance.

Aaron Garber wrote the music for "Job, the Oratorio," which was put on last year by the Salem Choral Society. The choral society also is producing Saturday's concert. Ryan previously set the "Magnificat" to music.

Ryan described the piano concerto as "middle of the road for my style, ... representing a variety of influences," including some that are "clearly contemporary."

"It's not too far out there, though," he said. In fact, its structure is "typical, with a fast first movement, slower, calmer second, and a fast and furious third movement."

Aaron's "Mass for Peace" is "not a political statement," he said, but was influenced by the fact that "we're not living in a peaceful world."

The attacks of Sept. 11, the war in Iraq and other events were motivations, he said, for the piece he began last summer.

"I always wanted to do a setting of the Mass," he said. "A lot of composers have done them back to Beethoven and so on."

Sandborg, a well-known soprano in the region, said the piece "feels in some ways like the way Mozart or Hayden or even Verdi would have written for the soprano voice."

"It's physically somewhat challenging for me," Sandborg said, written in a way "that has you in the rafters, hanging by your fingernails."

The tenor part for Leitch is similarly challenging, she said.

"The thing about Aaron's piece is that people will enjoy listening to it. While there is some dissonant writing, it's usually resolved. It's very, very accessible."

Aaron Garber's "Mass" omits the Credo section, which is fairly long, to keep the work to 42 minutes in length.

Ryan Garber said the two worked completely independently - so their works don't influence each other - but both were working with a joint premiere in mind.

"I've always wanted to write something for Melia," he said, "and this was the opportunity.""Mass for Peace" and Concerto for Piano and Orchestra will be performed Saturday in Shaftman Performance Hall at Jefferson Center. Tickets: $15, $18 and $20, available online,

www.jeffcenter.org

(866) 345-2550.