Fado, sometimes called the Portuguese blues, is a centuries-old folk style traditionally used to express saudade—nostalgic melancholy. It's an ideal vehicle for the kind of voice that makes people weep into their vodka and tonics, and Portugal's eminent fado chanteuse, Cristina Branco, 28, has such a voice.

On her recordings and in concert, her low, tremulous instrument is backed by a band consisting of a 12-string Portuguese guitar and a Spanish guitar, the traditional fado instruments, and a bass guitar. The 12-string guitarist, Custodio Castelo, is Branco's husband as well as her chief collaborator in songwriting. She presents him with a poem she likes, usually Portuguese, and the two of them craft it into song.

High-minded as fado may be in Branco's hands, the style had the rotten luck to be endorsed by the dictators who ruled Portugal for almost 50 years. For many Portuguese, the genre carried the odor of fascism long after a 1974 revolution restored democracy.

"It took 20 years for [fado] to grow up again, to be civilized music again," says Branco. Perhaps that accounts for the sense that even when she sings of desolation, Branco's delivery seems animated by the pleasure of recovering something lost. For her listeners, the pleasure lies in hearing a venerable art form lifted to new heights.