On Wednesday night, Lila Downs and her band played a small concert in Islington, London, to mark the release of her new album Shake Away . Downs was born in Oaxaca, Mexico. Her mother was a cabaret singer, her father an academic from Minnesota, and she alternated life between them, one year at a time. Mexico and Minnesota, Downs mused recently from a Tijuana hotel room, "are a long way apart - geographically, culturally, climate-wise. I feel divided within. But music has enabled me to express that."

In her Mexican life, she sang at weddings and quinceañeras (coming of age ceremonies). She nearly became an anthropologist. But an encounter with the political singer Mercedes Sosa changed her mind. "I thought, OK, you can sing but also sing about your convictions."

Sosa joins Downs on Shake Away for "Tierra de Luz", one of several songs about migrant workers. "All sorts of people need to leave their country of origin. 'Tierra de Luz' is about that: it's painful but rejoicing in life also."

Along with her husband, the American brass player Paul Cohen, Downs recorded a series of increasingly ambitious albums. In 2002, she was nominated for an Oscar for Best Song for "Burn it Blue" in Julie Taymor's film Frida.

She and Cohen divide their time between New York and Mexico City, as well as spending a few months each year in Oaxaca with Downs's mother. It must be exhausting. "It is but it's also really a lot of fun in terms of life and relations."

Does she feel more Mexican or American? "I wish I had all the positive traits from my American upbringing and all the positive traits from my Mexican one. From America there's a search for the truth, in an almost Lutheran way, that I hope I'm living as an artist and as a human being. But my soul is Mexican. I really relate to my Native American roots."

At the Union Chapel, lit with candles like a belated Day of the Dead, Downs and her band walked on from the vestry amid a howl and a rattle of rainsticks like singing winds and crying beasts. They launched into "Black Magic Woman", the old Fleetwood Mac song memorably covered by Carlos Santana. "It's about reappropriating a lyric I thought at one stage was misogynistic," she said earlier. "But now for me it's about female power and being OK with it."

The concert showcased her stylistic variety. On the ranchera numbers, the band swayed as if in a Bierkeller; "Minimum Wage", on record a rockabilly thrash, was throttled back a gear, trombone sliding and parping. "Justicia" became a triumphal march with a brass fanfare. "Los Pollos" saw exuberant chicken dancing, with an egg-laying waddle. For "Tierra De Luz", Cohen played a melancholy clarinet solo. On "Cumbia De Mole", Downs mimed enthusiastically, crushing together the chillies and chocolate of the eponymous sauce, rising from a throaty blues growl to a high wail.

At the end, Downs sang "La Llorona", an old fable about a woman who drowns her sons, kills herself, and comes back to haunt all men. She started in a voice as thick as a sob, over acoustic guitar, but ended kneeling at the footlights, keening, one notch down from a scream. ****

By David Honigmann

www.liladowns.com