Sister Gertrude Morgan's music wasn't remarkable for its beauty, its message, or its sophistication. Nevertheless, through a single album -- 1970s Let's Make a Record, recorded in New Orleans -- the eccentric figure best known for roaming the streets of the French Quarter in the 1950s and '60s and shouting invented spirituals through a megaphone made musical history, and not only within the narrow confines of gospel. Better than anybody who has ever set lips to a microphone, Sister Gertrude Morgan established an aural equivalent for outsider art.

For Sister Gertrude, born in 1900 as the seventh child of a poor Louisiana farmer, music was a natural extension of artistic inclinations that billowed around her from an early age. Though she was forced to quit school in third grade to help in the family fields, Sister Gertrude's passion for art remained tethered to her as tightly as her love of the Baptist Church. When the family couldn't afford art supplies, Sister Gertrude sketched figures and scenes in the dirt outside her childhood home with a stick. Married in 1928 to Will Morgan, she left her Louisiana home to live in Georgia. There, in 1937, she claimed to have had an epiphany one day while sitting alone in her kitchen. A voice, she said, enjoined her to "go and preach, and tell it to the world."

For Sister Gertrude, the world began in New Orleans. In 1939, she set about street-corner preaching there, and soon after opened an orphanage. After a hurricane devastated it in 1965, she opened a new outreach outpost in her home, the Everlasting Gospel Mission.

All the while, she continued to experience epiphanies: though her existence revolved around preaching, painting on whatever random objects she could procure (scraps of wood, Styrofoam trays), and helping the poor, she nonetheless dedicated herself to this unearthly voice. In 1957, after the voice assured her that she was the bride of Christ, she rid herself of her traditional preacher's black dresses with white collars and took to wearing only a white nurse's uniform. She also filled her house with all-white furnishings.

Local art dealer Larry Borenstein discovered Sister Gertrude's primitive yet stirring depictions of angels and sky scenes with swirling bits of scripture in the early '60s. The fine-art interest spurred an investigation of Sister Gertrude's ministry, where Borenstein became enchanted by her skills as an orator and performer.

In 1970, Borenstein recruited British sound engineer Ivan Sharrock to record Sister Gertrude in a wholly improvised session. What resulted was the landmark Let's Make a Record.

Take the Lord Along with You, she exhorts in a crackling, free-your-demons voice, and Take My Hand, Lead Me On. Her tambourine clangs sparely behind her. The music resonates in its simplicity and its guilelessness; in its spooky homespun truths and the scathing certainty with which they're delivered.

In the mid-'70s Sister Gertrude's art found its way to major museums, such as the Museum of American Folk Art. Though she died in her sleep at home in New Orleans in 1980, her art and her music continue to circulate, still earning awed accolades for their bare-bones profundity. ~ Tammy La Gorce, Rovi