Unlike Mariza and Moura, who don’t tinker with tradition much other than adding new songs into the fado repertoire, Zambujo isn’t too concerned with purity. On his fantastic fourth album Guia (World Village, 2010) he demonstrates a mastery of the style’s fundamental sound—a demonstrative delivery dripping with pathos amid a sweet weave of guitars (a standard acoustic guitar and the higher-pitched, chiming Portuguese guitar)—but he also freely moves outside of it. On some tunes he employs instruments rarely encountered in fado—tuba, dobro, clarinet, trombone, trumpet (Zambujo’s singing owes a noticeable debt to the soft focus croon of Chet Baker), and, on “A Tua Frieza Gela,” sound sculptures—and he artfully blends in elements of Brazilian pop music and even Cape Verdean mornas.

Zambujo grew up in Beja, in the country’s south, where he absorbed one of Portugal’s lesser-known traditions—Cante Alentejano, a polyphonic vocal style that bears similarities to traditions in Sardinia, Corsica, and Albania. On the singer’s excellent 2004 album Por Meu Cante (recently reissued by World Village) he concludes with a couple of excursions into this gripping a cappella form. All of his recordings, including Guia, find him reaching out beyond the strictures of fado like this; on the new record he sings a couple of tunes written by the great young Brazilian artist Rodrigo Maranhäo, who’s provided songs for Maria Rita and made a couple of terrific albums of his own, while a piece like “Zorro” sounds like a misty samba. And as you can hear in “Barroco Tropical,” below, he serves up his own fado-tinged morna—the ballad style made famous by Cesaria Evora—rippling with figures played on the sweet-toned cavaquinho

Zambujo performs tonight with bassist Ricardo Cruz (who also serves as the singer’s musical director), Portuguese guitarist Luís Guerreiro, and cavaquinho player Jon Luz. The singer accompanies himself on a conventional acoustic guitar.