If you want to lower your blood pressure, the high health priests say, simply watch an aquarium. All those beautiful fish, swimming around with such languid lack of purpose, will leave you feeling calm and at peace with the world. You can feel your fists unclenching, and before long, the little dents your fingernails make in your palms will be but a distant memory. Ah, sweet bliss!

Ladysmith Black Mambazo has the same effect on me. Their full-throated a capella chorus never fails to soothe; there is something relaxing, and joyful, in that sound. The songs are a sweet caress in a rough and tumble world, and every last one sounds like a lullaby. Ladysmith Black Mambazo could sing a song about my wife leaving me, my car breaking down, and my dog getting hit by a train, and I'm sure I'd find it pleasing -particularly if they were considerate enough to sing it in Zulu.

And so it goes on Raise Your Spirit Higher, the latest release from the South African stalwarts. There's a song about racism on there, a song about seatbelts (!), and a wedding celebration, but without the benefit of liner notes, you'd be hard-pressed to tell which is which. (I know, I know: when the Zulu craze hit, you were busy boning up on your Xhosa. Me too.) For us stateside mother-tongue music fans, the Ladysmith lyrics are lost among the intricate clicks, whoops, and inkululekos of the backing choir. No matter: above it all soars Joseph Shabalala's beautiful, breathy tenor, surely one of the most recognizable voices out of Africa.

(Here's a tip for you audiophiles: next time you go to the speaker store, leave behind your Stones, your Santana, your Flatt & Scruggs. Instead, slip in a disc of an a capella band with a great bass singer. The Persuasions' Jimmy Hayes gives a fine test of the low end, and Ladysmith boasts up to seven members singing bass at once. Basso profundo indeed.)

The Ladysmith story began, oddly enough, in the town of Ladysmith, South Africa, where Joseph Shabala was raised. The farm boy-turned-factory worker converted to Christianity in the 1960s, and proceeded to move the local isicathamiya vocal tradition in a new direction, adding a bit of European choral structure and seeding his songs with a gospel message. Ladysmith Black Mambazo gained regional fame, and that would have been that had a world music DJ not laid a tape in Paul Simon's hands in the early 1980s. Simon's Graceland gave Ladysmith their global debut, and their own Shaka Zulu took home a Grammy in 1987. Since then, they've recorded regularly; Raise Your Spirit Higher is as good as ever, filled with a sound that shows little age.

Which might be a problem, come to think of it. If Ladysmith Black Mambazo sounds timeless, it's because they very nearly are. As keepers of an a capella flame, they have less musical change to deal with, for good or ill: less innovation, less caprice. They have less of a stake in musical evolution: there is no digital wizardry to consider, no sampling, no backbeat, no ten-second break given to the global instrument du jour. (Today it's the bouzouki, I think.) It's just those same golden voices flowing together, as they have for forty years.

As glorious as those voices are, the texture rarely changes - at least for those of us who don't know Zulu. Over the course of an album, the experience can be a tad frustrating. World music fans encounter the language gap everywhere they turn, but it's not as much of a problem in traditional Afropop - just as it's not a problem in Cuban son, Cajun reels, or Italian opera. In those forms, the music provides enough variety to break the lyrical fog; just when you're fed up with having no idea what's going on, there's a guitar solo or a bongo fill to distract the ear. With Ladysmith Black Mambazo, it's just the voices, singing words we don't understand - except on those few tunes where they indulge a little English for the benefit of the international crowd. It's hard to dig beneath the surface when you don't know what they're saying.

Oh, but what a lovely surface it is.

It's hard to know what kind of live show Ladysmith Black Mambazo will give. Will it be beautiful? Yes. Buoyant? Yes. Compelling, relaxing, wise? Yes, yes, yes. Danceable? Probably not. Thrilling? Probably so. But will that thrill be sustainable for someone who doesn't speak the language? Maybe. Maybe not.

Tickets are $20 in advance and $22 at the door, and the show starts at 8 p.m. Call 828.225.5851 for more info.

Also Playing in Asheville

• Indigo Girls, Thomas Wolfe Auditorium, 3/5
• Dirty Dozen Brass Band, Orange Peel, 3/5
• RB Morris, Jack of the Wood, 3/5
• Dana Robinson, Grey Eagle, 3/6
• Primus, Asheville Civic Center, 3/10

Three Good Things

1. Huevos Rancheros
2. Crocus Blooms
3. Spring Training

They Said It

I'm not big on favorites, but my favorite movie of all time is Dr. Strangelove, which happens to epitomize our whole approach to making music. Here's an incredible comedy, with odd imagery, that's poignant, and a social statement.

- Primus' Les Claypool, as quoted in The Austin Chronicle.

Primus plays the Asheville Civic Center on Wednesday, March 10. Tickets are $30, available through Ticketmaster.