They may still not have found Carmen Sandiego, but international a capella sensation Rockapella will perform at CY Stephens Auditorium this Friday.

The show will be the group’s second performance in Ames; the first was in 2004.

High tenor Scott Leonard said the group has made some changes since then.

“It’s a completely different lineup since last time,” he said. “For the most part, people won’t recognize this Rockapella.”

The show is a single show following a short tour of Germany and Switzerland – the group’s first trip to Europe.

“Our American agent didn’t make it [going to Europe] happen, so I made it happen,” Leonard said.

He made the booking arrangements for the shows himself and said the European promoters were happy to work with him.

The trip brought the group into contact with fresh fans.

“It’s fun to kind of re-experience the band breaking,” Leonard said. “They’ve heard of us, but they haven’t seen us.”

An Indiana native, Leonard is very fond of playing in the Midwest and said he looks forward to playing in Iowa. The group will be playing in the state four times before the end of the year.

“I know it’s always fun there,” Leonard said. “It’s amazing how many places there are to play in Iowa.”

History

The group’s origins date further back to 1986. Rockapella was founded by four Brown University alumni, none of whom are still in the group.

At the time, a capella music had a very small following, and the group played small gigs and street corners in New York for some time. During one of these street corner performances, they met a television producer who secured a spot for them on the show “Spike & Co.: Do It A Capella,” bringing them their first recognition.

It was then, in 1991, that Leonard joined, responding to an ad placed by the group. Shortly after he joined, Rockapella was offered the position as house band on “Carmen Sandiego,” introducing them to the entire world.

“Before that TV show hit, it was more like a struggling day job thing,” Leonard said. “Who knew this TV show would be such a big thing?”

From there, Rockapella’s exposure expanded to include TV commercials, talk show appearances and, eventually, albums and live shows.

“‘Carmen’ was really revelatory about the power of television,” Leonard said. “The way it changed our careers was amazing.”

They did have some initial difficulties being accepted as something more than a children’s or novelty act. Their first record deal was made in Japan, where record companies and audiences were more open to the group’s sound.

“We really introduced the whole genre of modern a capella to Japan, and it really took off,” Leonard said.

This breakthrough was able to knock down the barriers that had existed for the group in America, and they started performing domestically shortly thereafter.

Since then, Rockapella has continued to develop their sound and write new music.

“It’s really evolved since then, the so-called art form of a capella,” said vocal percussionist Jeff Thacher.

Lineup

The lineup of Rockapella has never been steady, as members join and leave for other projects. Leonard, who has been with the group since its 1991 debut on “Where in the World is Carmen Sandiego?,” is currently the most experienced member.

Since Leonard joined, all of the original group members have moved on to other projects. Additionally, the lineup changes every few years. An important addition to the lineup was Jeff Thacher, vocal percussionist, who has been with the group since 1993 and performed on the last season of “Carmen.”

Thacher, rather than singing a traditional vocal part, does what he calls “mouth drumming” – mimicking drum sounds with his mouth. Trained as a traditional vocalist, vocal percussion began as an experiment, and some of his work was sampled for use on “Carmen,” in lieu of real drums.

“I realized there was something there if someone wanted to run with it,” Thacher said.

Since Thacher started, the vocal percussion field has expanded somewhat, notably with the hip-hop practice of beatboxing, but Rockapella was there at its beginnings. After he joined the group, Rockapella has gone through three more lineup changes. Tenors Kevin Wright and John K. Brown, and bass vocalist George Baldi fill out the group.

Interestingly, every member of Rockapella has worked for Disney’s theme parks at some point. Thatcher said he likes to joke that, whenever the group needs a new singer, they can recruit from Disney. The group sees this gradual change as positive development.

“As the baton is passed from one group to the next, we’ve tried to upgrade,” Thacher said. “I think this is the best we’ve sounded.”

The changes aren’t simple tweaks in sound, however, but an evolution.

“It’s really a new Rockapella with the guys we’ve got,” Leonard said. “It’s more about the music and the show and the entertainment, not the shtick any more.”

Music

Leonard does all the songwriting for Rockapella, recording everyone’s parts. The other group members then learn from that, and they put it all together at sound checks and rehearsals.

Because of the skill of the musicians and the lack of instruments, composition is a fairly simple task for the group.

“All that’s required is to sing well and have a good ear,” Thacher said. “I think that’s really the art of what we do.”

Rockapella has created a massive catalog of songs during their history, and about half of these are original – something Leonard says is unusual for an a capella group.

“Most [a capella] records are all covers,” Leonard said. “We’ve got to show it’s about original music – it’s about the material, not how you do it.”

Covers are an important part of Rockapella’s music, but they’re very selective about what songs they perform.

“I don’t want to do a Beatles song just to say we did a Beatles song,” Leonard said.

He said the covers they performed had to be surprising and “earn their right” to be a part of their show.

Most songs Rockapella covers are pop songs from the ’60s and ’70s, along with a few Motown tracks. So far, the group has refrained from covering any newer material.

“It’s best not to revisit that stuff too early,” Thacher said.

Leonard, however, said he may be getting into some ’80s material soon.

File sharing

Rockapella has an unusual relationship with file sharing on the Internet. Many a capella covers not performed by Rockapella are misattributed to them in names of files distributed through peer-to-peer services.

Many of the mislabeled songs are tracks from the ’80s – a period the group has not yet touched.

Leonard attributes some confusion to the group’s name.

“I think just a good name for the genre is Rockapella,” he said.

Thacher said it’s fairly easy to tell whether a song is genuine.

“If it sounds like a group of 15 guys, it’s not us,” he said.

Rockapella’s Web site, www.rockapella.com, also lists all the covers the group has performed.

Unfortunately, some fans are taken in by these mislabeled songs, and they end up requesting them at concerts.

Other than this misidentification phenomenon, Rockapella loves the Internet.

“I don’t really have a strong feeling about copyright enforcement,” Leonard said. “I think it’s all good exposure. I think the more we can connect, the better we’ll all be.”

The future

Although the group members all have various side and solo projects, including Leonard’s recent record, “1 Man 1 Mike,” Rockapella is still going strong.

“It’s amazing to me how the band has sustained itself for 16 years,” Leonard said.

Despite the amount of work involved and the fact that the group members all have families, they still enjoy performing.

“It’s still a lot of fun for me, so I don’t see an end to it,” Leonard said.

“We’ll just keep spreading the gospel of Rockapella.”