Nashville-based, classically trained harpist and vocalist Timbre Cierpke — a.k.a. Timbre (pronounced “tambour”) — isn’t your typical Music City singer/songwriter. She plucks and strums an unusual blend of classical music, ambient pop, and post-rock on a full-sized classical harp. There’s nothing country about her refined, well-orchestrated songs. Timbre returns to Charleston for a special concert on Saturday evening at the Circular Congregational Church in support of her nine-song 2010 studio album Little Flowers. The atmospheric set features her operatic voice and harp along with strings, brass, choir, drums, guitar, bass, and accordion. She’ll share the stage with local act Mechanical River, a.k.a. Joel T. Hamilton, who recently released a self-titled, self-produced debut album (see review). Show time is 7 p.m. The concert is presented by Awendaw Green.