It's rare that I get concert recommendations from Warren Haynes.

In fact, it's never happened. Ever. Well, until the other day.

As I wrapped up an interview last week with the omnipresent rock guitarist on the new Mule album to be released next month, I mentioned to Haynes that I was going to catch two of his friends Alvin Youngblood Hart and Vusi Mahlasela play an intimate acoustic gig the following week in San Francisco.

"Oh, man," Haynes said in his gravely Southern drawl. "Those are two of my favorite musicians. I'd pay big money to see those two guys play on the same bill. I wonder if they'll play together at some point?"

As I wandered into a rare, candle-lit, chairs-and-table-fashioned Independent last Thursday night that resembled something closer to a dark jazz club than the venue's normal standing room only setup, I too pondered the same question: Would we witness the collision of the Mississippi Delta blues music of Alvin Youngblood Hart and the passionate, revolutionary voice of South African Vusi Mahlasela?

At first glance, the music of Hart and Mahlasela might seem as different as the two worlds in which the musicians live. Born in California in the 1960s and raised on the music of great American bluesmen Charlie Patton, Robert Johnson and Taj Mahal, Hart is a throwback to an era when unplugged meant playing on your front porch. In this day and age when the revival of African-American blues music is being credited to a kid with the last name White, Hart's music reeks of an authenticity noticeably absent from anything coming out of Detroit.

Mahlasela is also a child of the 60s, raised by his grandmother in the Mamelodi township outside Pretoria, South Africa. He grew up listening to people singing in his grandmother's shebeen, a kind of township watering hole, and taught himself to play the guitar on makeshift instruments constructed of empty cooking-oil cans and fishing line strings. Soon after, Mahlasela started writing songs addressing the social injustices of apartheid and performing at political rallies across the country.

For his opening set, Hart stuck to his electric guitar and played songs from all three of his great studio albums 1998's Territory, 2000's Start With the Soul and 2002's Down in the Alley. Hart's slippery slide guitar work and deep, throaty growl transported the audience to the sweltering juke joints of the Delta. He closed his set with an intense version of "Big Mama's Door," the title track off his first album.

Mahlasela's set featured songs from his U.S. debut album, The Voice, which was issued by fellow South African Dave Matthews' ATO Records label in 2003. A fantastic acoustic guitarist, Mahlasela's melodic playing served as the perfect companion to his unique vocals, which were heavily influenced by the a capella "mbube" music that the legendary group Ladysmith Black Mambazo made famous and later recorded with Paul Simon on his seminal 1997 world music album, Graceland.

Hart and Mahlasela never did share the stage. Unfortunately, Alvin flew in for the gig the morning of and had to leave the venue at the outset of Mahlasela's set to catch a red-eye flight back to the East Coast for a show the next day. Yet, as different as their backgrounds may be, Hart and Mahlasela's performances last Thursday night displayed the common bond shared by these two immensely talented musicians passionate songwriting delivered through two very distinct, authentic musical voices.