Matt Oltman knows there are a lot of varying ideas about what Chanticleer is among music lovers.
"I love it when people identify Chanticleer as a group that performs early music or a group that does jazz as the main thing," says Oltman, music director of the San Francisco-based male vocal ensemble. No matter what style of music the group presents, "we try to perform music in as authentic a way as possible. There's a fine line between performing gospel music and imitating gospel music."
Gospel music is merely an example of the wide variety of styles that Chanticleer, which performs Monday at Centre College's Norton Center for the Arts, presents and works to get right.
Perfecting a style might involve diction lessons, cultural anthropology and any number of other methods to get the 12-voice a cappella ensemble to present an authentic rendition of whatever it chooses to present.
Oltman, in his second year as artistic leader of the 33-year-old ensemble, says there have been extremes in this goal, such as trying to get their voices around a piece by Chinese composer Chen Yi — about clay figurines — that was composed primarily of "nonsense syllables."
"We didn't even have words to hang on to. We had to figure out what it was about clay figurines that compelled her to write this. We really looked at how she responded to these outrageous faces and comical looks, and we emulated that."
Oltman has to look no further than the centerpiece of the group's current tour program, about "spiritual and metaphysical views of space," to see another monumental interpretive task.
That piece is Observer in the Magellanic Cloud by Bay Area-based composer and DJ Mason Bates. The piece supposes a brief meeting of Earth's distant past and future when a lost satellite spots the ancient Maori people of New Zealand from light-years away.
"What does a satellite sound like?" Oltman says. "How does a satellite sound excited, and what whirrings and ringings would have emotion? We had to create a being that doesn't exist."
The piece by Bates, with whom Chanticleer has worked before, spurred the group to put together the "Out of This World" program. Once he had that, Oltman built around it with pieces medieval to modern that contemplated and celebrated the heavens, including one piece that walked through the Chanticleer door.
"I was in my office one day, and Kirke Mechem, a composer who is based in the Bay Area, came in with a stack of music and said, 'I can't believe Chanticleer and I have been in the same city all these years and you've never presented my music,'" Oltman says. "I said, 'Well it's going to happen now,' because right there he had Island in Space, which was perfect for this program."
Chanticleer's authentic representations of wide varieties of musical styles have helped earn the group accolades, but another piece on Monday's program represents a more traditional avenue to acceptance in classical music.
Gustav Mahler's Ich bin der Welt abhanden gekommen puts in their voices a piece that has been performed by many singers, orchestras and conductors. It's a daunting task, particularly when Chanticleer performed it on Mahler's home stage, Musikverein in Vienna, Austria.
"You have to realize you are in the line of a great tradition," Oltman says of performing Mahler on Mahler's stage. "So when we performed it and the audience applauded it, we knew we were on the right track."
Fans of a wide variety of music would agree.