BUENOS AIRES, Argentina -- You can hear the "All of us are crazy for tango" program before you can see it: Just follow the orchestra's plaintive chords through the labyrinthine passageways of the Hospital Borda.

There, in a dance hall deep inside the public hospital where mentally ill men have been treated for 150 years, both patients and visitors discover how much they have in common in dance classes open to all. The program's name, playing off a common expression for mental illness, reflects the enthusiasm of both patients and visitors for Argentina's national dance.

Psychiatrist Silvana Perl runs the classes held every other Wednesday, including their annual tango festival this week.

She says therapy happens when hospitalized men dance with visiting women: It makes them part of a powerful social and cultural current that runs through Buenos Aires, and gives both dancers the shared human contact that is essential to community.

"To dance, it's necessary to include the other, which requires coming out of your little world," Perl explains. "Then comes the hug ... the whole world is now fascinated with hugging, which is a form of communication. And 'communication' comes from what we have in common. This is something that we have in common, this hug of the tango."

Tango teacher Laura Segade says she and her friends joke that the only difference between the dancers is that some are "crazy on the inside" of the hospital and others are "crazy on the outside."