Sorting out costumes, setting up microphones, laughing and eating Christmas cookies is the way the Pennharmonics starts its final dress rehearsal.

At 10 p.m. tomorrow night, the a cappella group will take the stage in the HUB-Robeson Center's Alumni Hall for a performance that will be its 10th anniversary concert, as well as its biggest reunion show to date.

"We have 10 years worth of alumni coming back for this show," music director Adam Giesy (senior-electrical engineering) said.

Two groups of alumni will perform at the concert, one composed of the first five years, and the other composed of the second five years.

"The alumni are only getting one chance to rehearse together, Saturday morning," Giesy said.

Most of the Pennharmonics' concerts consist of 10 to 14 songs; this concert will showcase 22 songs.

Brian McKinney (sophomore-mechanical engineering), a Pennharmonics member, said he's excited to see all the old alumni.

"I'd like to the see their reactions to some of our newer stuff, plus we have some surprises for the concert-goers" McKinney said.

The 16-member co-ed group performs without any accompaniment, mimicking the sounds of various instruments with their voices.

The group performs traditional songs along with newer songs by the Indigo Girls, and Matchbox Twenty.

The women of the group put together a special performance of "Lady Marmalade."

Sitting back and watching the women rehearse, Dan Brian (junior-crime, law and justice) smiles.

"I don't understand why anyone would join an all-guy group," Brian said. "But that's not why I do it. I do it for the love of the music."

In April the group was recognized as one of the top five a cappella groups in the world when they competed in the International Championships of Collegiate A Cappella.

The only Penn State group to compete, and the youngest, since it was founded in 1993, the Pennharmonics had the opportunity to perform on the Broadway stage.

"Performing on Broadway is every singer's dream," assistant music director Sita Palomar (junior-advertising and theatre) said.

"To be on stage with people you love and know that you all helped one another to get there is the most incredible feeling."

The group is not an official Penn State organization, and as such doesn't receive any university funding.

"Our monetary status is dictated by our ticket sales" Giesy said.

Saturday's concert is in connection with Late Night Penn State, which Giesy said has been instrumental in helping the group gain exposure across campus.

"We're breaking new ground by letting Late Night sponsor the concert. We hope it's only the beginning," Giesy said.