For sisters Leah and Chloe Smith of Rising Appalachia, there was no “aha” moment when they realized they could sing. They simply grew up doing it.

“Our family was very musical and our mother used to sing harmony notes into our ears so we would begin hearing the many layers of sound organically,” Chloe Smith says. “She also had a fantastic women’s singing group meet at the house once a week for years for simply the joy of singing in harmony, and Leah and I sat in with them as late teenagers to try out our own voices.”

The Smith women are now over the learning-curve hump. Since 2005 they have released five albums, one digital album and a DVD. Their Southern hippie meets jazzy lounge style provides plenty of reference points, but nothing pointing directly to them. They are fire dancers, sport dreadlocks and wear face paint. Unabashed treehuggers, the sisters evoke historical Southern song styles and rhythms while making them their own.

The two sing, alone and together, accompanied by fiddle, bass, banjo, drums, trumpet or nothing at all. They chant, wax poetic, laugh, swoop and soar with harmonies that bring goosebumps.

“There is a sort of blood-line harmony that only siblings can do,” Chloe says, “because our vocal chords are cut from the same cloth.” So are their answers. We exchanged emails while the pair were in Canada — they answered together, so it was impossible to tell which one said what unless the other sister was mentioned.

On this tour Rising Appalachia is joined by one of the most dynamic spoken word artists in the country — Theresa Davis. A new Rising Appalachia album is coming, and the girls have recently collaborated with Dirtwire (David Satori from Beats Antique and Evan Fraser), who play Cozmic Sept. 18, and Medicine for the People.

“We receive great influence and inspiration from collaboration and community building and are always humbled and lit up by the work of our friends and cohorts,” they say.

Rising Appalachia plays with Theresa Davis and Will Brown 8:30 pm Saturday, Sept. 20, at Cozmic; $15 adv., $20 door.