The Stone Church was packed for Sarah Harmer’s acoustic show in support of her new album, “I’m a Mountain,” despite the snow and the cold that would have kept fans of other performers home. The show opened with the Shiftless Rounders, a rootsy duo with a little ’70s singer-songwriter vibe coursing through their banjo and slide guitar interpretations of mountain music (it might be me, but I had more than one flash of Pure Prairie League and early Loggins and Messina, perhaps evidence of the multifaceted folk heritage from which the Rounders have emerged).

But the emphasis on pure Americana quickly shifted when Harmer took the stage with her band. Including mandolin, flute, clarinet, violin and stand-up bass, Harmer’s band creates an old-world musical texture that evokes French-Canadian folk traditions, a potent reminder that not all folk music derives from American folk and proof that Harmer has incorporated both the roots of her own musical heritage as well as the technical excellence of many contemporary folk artists into her own unique sound.

The music is appropriate to Harmer’s richly multi-layered lyrics, which are laced with potent observations and evocative imagery, effortlessly drawing the audience into her contemplative emotional world. A wise lyricist, she trusts her audience to understand her songs without reciting extensive background stories between them.

But the most mesmerizing aspect of Harmer’s performance is her voice: Harmer draws listeners from all over who are willing to travel to hear her clear vocals, which ring like the sweetest bells with one of the purest tones in music. Like most artists on tour to support new work, she sang most of her new album, opening with the upbeat ode to new love, “I Am Aglow” and closing the nearly a cappella  “Deep in the Valley.”  In between the new songs, older works like “Uniform Grey,” “The Hideout,” and the beloved and powerful “Lodestar” blended seamlessly with the new, showcasing Harmer’s consistent ability to create tightly crafted songs in which the mood of the lyrics is always matched with appropriate music.

Added to the power and beauty of her songs and her voice is her unmatchable stage presence. Harmer is a gracious performer, asking for requests from the crowd and revealing a deep respect for and admiration of other musicians, especially Canadian colleagues like David Hodges and Luther Wright, whose work she covers and credits as influences. Finally, her natural charm gives her stage presence a directness and honesty that creates an intimate environment. The combination is a knockout punch: Harmer welcomes the audience into her music and her performance in a way that few performers can.

A subtle education in more global expressions of folk music and an expert display of finely crafted songwriting, Harmer’s show feels like a cozy night by the fire with a warm and gifted friend that you hope will stay for a long time.