'I don't know, a little bit of everything," says Afro-Spanish singer Concha Buika, when asked for further details on what her return to the Kimmel Center's Perelman Theater stage on Thursday might offer. "If I say I'm going to sing this song or that song, that I'm going to do this or that - then, when I'm on stage, I go into a kind of trance and everything is completely different. I don't rehearse a set order, I just go on stage and try to reason what I'm singing."

The results delivered by this exuberant daughter of African exiles - she was born and raised on Mallorca - have been widely acclaimed across the continents. When the jazz-tinged, flamenco-informed Buika made her riveting Philadelphia debut at the Perelman in October 2010, she was showcasing El Último Trago, her adventurous 2009 collection of songs associated with the long career of late Mexican ranchera diva Chavela Vargas. This time around, she's ostensibly presenting her latest, last year's La Noche Más Larga, a heady mix of personalized classics and originals. But where things will end up is unknown.

"Because the people in the theater, the tribe, my tribe, they are the ones who determine the direction of the show," she elaborates. "There is a lot of information running around the theater when you're on stage, a lot of things happening. If you listen carefully, you know where to go. If you do your job - and your job as a musician is to listen - then the magic makes you play. If you plan it, if you set it up, it doesn't work."

Such in-the-moment spontaneity is clearly facilitated by the gifts Buika possesses: smoky, richly textured vocal tones that have invited serviceable comparisons to Nina Simone and Cesária Évora; the abilities to tap into deep emotion in her interpretive phrasing, to articulate fresh nuance or make shattering statements on love and loss that transcend language.

Through seven studio albums, she has traversed jazz standards and pan-Latin material while always giving things a complicated, cross-hybridized twist. At the core, however, is a discernible grounding in the music of the gypsy neighborhood in which she grew up: "Girls from other neighborhoods would go to the cinema or go shopping, but in our neighborhood, we didn't have the money. So the gypsy girls and me, we didn't have much else to do - and what we did was learn how to clap, and sing flamenco all the time."

She's still evolving artistically, and her influences range from Tina Turner to beyond her mother's nurturing jazz and pop record collection, so Buika, now Miami-based, is wise to eschew any pat categorization. "I'm not a flamenco singer, of course not," she says, "but I have some flamenco sounds in my head. Why? Because I learned how to survive with that. I have some hip-hop in my head. I don't know anything about hip-hop. I don't know anything about flamenco, jazz, blues, rock - I just know how to use in the right moment!"

A key, consistent element in Buika's instrumental sound - and contributing to its underlying flamenco feel - is the cajón, a wooden box drum of Peruvian origin. The innovative late guitar master Paco de Lucía brought it to flamenco in the '70s, inspired by how well it effected the genre's percussive sounds. Hailing from an esteemed Spanish flamenco family, Ramón Porrina, Buika's longtime collaborator, as well as co-producer of La Noche Más Larga, is considered a cajón virtuoso of the first order. He'll accompany her here, along with Armenian guitarist Vahagn Turgutyan and Cuban bassist Yadam González.

"The cajón to me is an instrument that has a little heart," Buika assesses. "I don't know why, but when Ramón plays the cajón, I feel like a little heart is beating next to me. No matter what the rest of the musicians are playing, if Ramón is playing and I don't have any shoes on, I cannot get lost, it's completely impossible."

Buika plays at 7:30 p.m. Thursday at the Kimmel Center's Perelman Theater, 300 S. Broad St. Tickets: $29-$39. Information: 215-893-1999, www.kimmelcenter.org.