A happy World Cafe debut of 43-year-old Os Mutantes

Warm smiles were all around at World Cafe on Monday, from audience grins growing ever-wider to the joyful Brazilian band onstage: Os Mutantes, the ethno-psychedelic rock-pop group making its area debut 43 years after formation. True, Brazil has a renowned festive disposition: Its peerless soccer team has won five World Cups grooving to a samba beat. But Monday night saw some especially infectious reciprocation between Philadelphia and São Paulo.

Only singer-guitarist Sérgio Dias Baptista, 57, remains from the original Os Mutantes lineup. They were the precocious electric-rock youngsters of the late-'60s/early-'70s tropicália movement, anchored by titans like Caetano Veloso, Gilberto Gil, and Jorge Ben, all of whom wrote songs Os Mutantes covered then and Monday, such as "A Minha Menina," "Baby," and "Bat Macumba."

The current septet - including veteran drummer Dinho Leme (1971) and essential female vocal foil Bia Mendes (joined since Os Mutantes' 2006 reformation) - easily provoked the crazed exuberance required to hold up the band's legacy, one that has inspired many discerning rock undergrounders (Beck named his 1998 album Mutations in tribute).

Still wearing the signature black cape he donned on their first album, Dias blazed on his customized guitar through hard-rocking classics like "Jardim Elétrico" and the recent "Neurociência do Amor" (from this year's Haih Or Amortecedor), and evoked Paul McCartney at both his tender piano-ballad and raging "Helter Skelter" art-noise-nik best on "Balada do Louco." Whether presented in English, Spanish, or the predominant Portuguese, the 15-song set exhibited a thrilling mastery.

The evening's first foreign language was showcased by openers DeLeon, who sing mostly in Ladino, the Judeo-Spanish spoken by Sephardic Jews, a linguistic vestige of centuries living in Spain before their expulsion in 1492. Fronted by singers Dan Saks and Amy Crawford and named after Moisés de León - the 13th-century Spanish rabbi believed to have authored the Zohar, a key Kabbalah mystical text - the Brooklyn-based band zipped through a set of songs over 500 years old with a tuneful indie-rock zest.

So, has the planetary lingua franca of rock run out of fresh sociocultural elements to absorb in creating intriguing new subgenres yet? Obviously not. To use the title of the laudable 1999 Os Mutantes collection that fan David Byrne compiled, Everything Is Possible.