Man, I hate authenticity these days.

All this media bullshit about Barack Obama not being "black enough" has put me in a fluster over our cultural worship of the authentic background. Every celebrity's biography, it seems, is geared to prove that dues were paid and obstacles overcome in some vague, holy quest to "stay true." We're bombarded with these backstories and we eat them up.

We demand authenticity in music, don't we? Music that comes from a true source, whether way down in the swamps or high up in the hills, is our cultural grail. We hunger for a living representation of purity, someone upon whom we can bestow the ultimate honor: being the "real deal."

But this phenomenon's all-too-common opposite--writing off anything that blurs particular prejudices of geography, economic status or race--is a dangerous practice at large, and extremely limiting for music in particular. What if a milk-faced kid from Tupelo had never discovered rhythm and blues? What if four straight-edge guys from D.C. had enrolled in grad school instead of starting a hardcore band? What if three girls from Texas had never broken through country music's blind support of the president?

Where would we be then? I'll tell you: we'd be listening to the same 29 Robert Johnson songs over and over again, stagnating in a pool of self-imagined authenticity. In fact, I know some of these people, and take my word for it, they are not an exceptionally happy bunch.

I don't mean to be purely reactionary here. I'm simply explaining my own shortsighted judgment when I first discovered that Lila Downs, the sensational Oaxacan-born singer of Mexican rancheros and spirited carrier of the Mesoamerican tradition, had actually been raised in America by a Scottish-American father, graduated from the University of Minnesota, sung jazz in Philadelphia and for a few years--sin of all sins!--followed the Grateful Dead around the country.

My mind reeled. My knee jerked. How could this be? Inside, I felt the distressed pang of being duped.

But I decided to immediately listen again to Downs' latest album, La Cantina, in an experiment to determine if her music had, in fact, been tarnished by this new revelation. It hadn't. Moreover, the very elements in her music that betrayed a traditional Mexican heritage--angular big-band arrangements, drum and vocal loops, a cappella choirs--were the same distinctive elements that drew my attention to Downs in the first place and opened me to the powerful emotional range of her rich, throaty interpretations of native Zapotec, Maya, Nahuatl and Mixtec Indian songs. She appears at Yountville's Lincoln Theater on March 23.

Over the phone from a Hollywood hotel last week, Downs admits that she's taken knocks from hard-line traditionalists for not being "authentic" enough, but she has the sage detachment to laugh about it. "I'm sure that I do get criticized," she says. "I've heard of some in Veracruz. But of course, nobody tells me to my face."

Why would they, when every musical tributary that Downs has explored has only enriched her palette? Through singing jazz standards like "God Bless the Child" or "Tenderly" at smoky clubs in Philadelphia, she picked up a deceptively uninflected phrasing that she employs to fragile degree throughout La Cantina. "I think it's always a point to come back to, the standards," she explains, "and to somehow always envision that life."

Through singing tango music in the highly acclaimed movie Frida, Downs was able to reach a wide audience--and to help liven up the Academy Awards show in 2003. "It was kind of a somber time," she recalls of the broadcast. "I remember that the war had just begun, I think, the day before. So we were all kind of just a little quiet. I remember that Michael Moore was there, and that," she laughs, "was kind of a relief."

A move to New York City allowed Downs to assemble an outstanding multicultural band, incorporating electric instruments and modern production. "I really dig the electric guitar," she says. "It just kind of opens your soul, you know, and it opens lots of different things, the way that you feel about life, and you can let loose."

There's one musical avenue that didn't stick, however. Despite seeing the Grateful Dead night after night, Downs shows an uncanny lapse in memory when it comes to the band's music. If you can remember it, as the saying goes, you weren't there, and when asked what her favorite Dead song is, Downs clarifies that she was, in fact, there.

"Yeah, I think I have, uh, several that I kinda, that I like," she stumbles. "I like, uh, uh, let's see . . . There's a song that goes, 'Friend of the devil is a friend of mine.' I like that song, it's pretty cool. It's renegade, it's that kind of thing. And that was really one of the reasons that I was attracted to that whole scene, was kind of like droppin' out, you know, that whole thing that we have to go through in life."

Has she ever regretted following the Dead instead of pursuing her own music? "I don't think you can ever turn back once you go in that direction," she insists. "I mean, for me, it wasn't ever just a phase. It really made an imprint on my life, and it made me believe in certain things and I try to stick to those things."

Now, on the eve of an acoustic West Coast jaunt, sandwiched between tours of New Zealand and Spain, Downs is looking forward to spending time, she says, in California, where the Mexican population "has so much to do with who I am as an individual, these issues that have to do with migration and the Mexican-American community." Downs' 2001 album Border explored the immigrant experience.

Of course, despite the vineyard-worker population, Napa Valley is for the most part a very upscale area, and I ask if, when she performs in regions like this, she's still able to connect to the people of the community that gave birth to her music. "I hope so; I mean, that's one of our challenges--always trying to bring audiences together," she offers, having earlier in the day filmed a television special for Univision and about to conduct an on-air interview for NPR. "We're very lucky, our audiences vary quite amazingly.

"The question is finding a way that the music can bridge those gaps between people who are in different walks of life," she stresses. "I think that's very important, so that people aren't so afraid of one another."

Lila Downs performs on Friday, March 23, at the Lincoln Theater, 100 California Drive, Yountville. 8pm. $25-$50. 707.944.1300.

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