Sonnambula is a preeminent Renaissance Baroque ensemble specializing in music from the age of Shakespeare, Milton, and Moliere. Whenever they play their beautifully replicated instruments, I find myself entranced by the spell they cast. The Italian word sonnambula–famously used in the title of a Bel Canto opera by Vincenzo Bellini–means “somnambulist.” If you’re wondering what sleepwalking has to do with seventeenth-century chamber music, the answer lies in the understated intonation of the delicately constructed, gut-stringed viola da gamba, which resembles a cello but sounds more like an enormous bowed lute. A statement on Sonnambula’s website refers to the instrument’s “quiet beauty … the sort of which is difficult to come by in today’s loud and fast-paced world.” To paraphrase the Bard: something gentle this way comes.

Those who love both cats and stringed instruments will be happy to learn that, contrary to popular belief, the worrisome word “catgut” does not refer to feline viscera. Authentic gut strings are generally made from the intestines of sheep, cows, or goats. This natural fiber produces a sound that is more organic, so to speak, than the brighter intensities of modern steel strings. Possible origins for the term catgut include “cattlegut” and “kitgut,” named for the gut-string pochette, pocket or kit fiddle. Gut-strung viols and similarly soft-spoken instruments were originally played in private residences rather than concert halls; this is one origin of the term “chamber music.”

Structurally and acoustically, St. Andrew’s Episcopal Church is well suited for period instrument performance. Sonnambula’s concert in that space on September 21 will feature music by Leonora Duarte, whose complete surviving works consist of seven short fantasias for five viols. Duarte’s family survived the Portuguese Inquisition as conversos–Jews who converted to Catholicism under duress and faced additional persecution when accused of secretly continuing to practice their original faith. After emigrating to Belgium, the Duartes became established merchants who supported and mingled with Antwerp’s artistic community; the painter Vermeer was a friend of the family.

Leonora Duarte was born in Antwerp in 1610 and raised in a stimulating cultural environment where she learned to compose music for viol consort. According to gambist, musicologist, and Sonnambula artistic director Elizabeth Weinfield, Duarte was never commissioned to write music for court or church because she was female and Jewish. Instead, her works were tailored for and performed within intimate domestic settings. Sonnambula’s program will also include music by other seventeenth-century composers, illustrating what Weinfield describes as “the complex and symbiotic relationship that Duarte had with her male contemporaries.”

Sonnambula presents “The Salon of Leonora Duarte” September 21 at St. Andrew’s Episcopal Church.