It’s almost as easy as saying one’s a little bit Broadway, one’s a little bit smoky cafe. But despite the differences in their singing voices, the Sisters Callaway – Liz and Ann – have carved a niche for themselves in the history of family music acts.

When they appear Saturday, May 1, at the Maine Center for the Arts in Orono, the two crooners will present a hybrid version of their highly acclaimed cabaret acts: “Sibling Revelry” and “Relative Harmony.”

“Some people call it a concert or a cabaret show,” said Liz Callaway, speaking from her home outside of New York City. “But it’s more than that because there’s a theatrical through-line to the show, and it’s biographical. And Ann and I have a lot of fun.”

The fun began a lifetime ago, when they were girls growing up in Chicago. Because their mother taught singing and was a singer, music was a part of their household. After each of the girls – first Ann, then Liz – showed an interest in the business, it seemed logical for them to move to New York City. So when they were 18 and 21, they went to “make our fame and fortune,” as Liz joked.

As it turned out, it was no joke. Ann began playing piano bars. Liz took a job waiting tables, but within a year she was cast in her first Broadway play – “Merrily We Roll Along” by Stephen Sondheim – and within that same week, she was also cast in an off-Broadway production of “Godspell.” Because the Sondheim play was postponed for eight months, she was able to take both gigs, plus did another off-Broadway show and a movie before the Broadway role.

“After that,” said Liz, “I went back to being a waitress.”

But, she added, there was no question that the sky still remained the limit.

“Our parents really gave us a solid foundation that we would be OK no matter what,” said Liz, who has a 13-year-old son with her husband, Dan Foster, a theater director. “They gave us confidence in ourselves. I did not move to New York City because I wanted to be a star. But I knew I would always be OK.”

As it turns out, the sisters have, separately and together, been more than OK. Each has been nominated for a Tony Award. Liz took an Emmy Award for hosting “Ready to Go,” a children’s program, and Ann has received national attention for writing and performing the song “The Nanny Named Fran” for the TV comedy “The Nanny.” Each of them has solo recordings, as well as film and TV credits.

The show they do together, both said, is not only great fun but a chance for them to visit in the midst of demanding career commitments that keep them apart. Plus, there’s nothing like singing with your sister.

“It’s always a revelation to sing with someone you’ve known your entire life,” said Ann Hampton Callaway from her hotel room in Hollywood, where she was performing a solo show, being fitted for a role in an upcoming movie and researching a tribute to Peggy Lee. “Nobody knows me as well. There’s a level of emotional intimacy and psychic connection. It’s a DNA blend.”

As with many sisters, there is also an element of competition. Both spoke of feeling pangs of jealousy about the other’s career, but it’s just pangs, they quickly added. Clearly, each has celebrated the triumphs of the other.

“We’re very sensitive to one another,” said Ann, who still lives in New York City. “We know we have to be allies. We joke about one-upping, but we’re supportive, and we really want each other to shine. God made us different enough so that we’re more complementary than challenging.”

One critic described the distinctions in their voices in terms of other pleasures. Liz, he said, was champagne and ladyfingers, and Ann was port wine and Havana cigars.

Ann put it another way: “I like to call Liz’s voice sunlit and mine moonlit.”

Sisterhood, as the saying goes, is powerful. In the case of the Callaways, it is also sure to be tuneful.

Liz Callaway and Ann Hampton Callaway will perform with their trio at 8 p.m. Saturday May 1 at the Maine Center for the Arts in Orono. For tickets, call 581-1755. Alicia Anstead can be reached at 990-8266 or aanstead@bangordailynews.net.