By Melany Klinck

Every year, exactly 50 days before the first full moon following the vernal equinox sambistas take to the streets of Brazil. For four days, their hearts pound in sync with the beat of the surdo. Their voices, united in song, echo down broad avenues. And their bodies move with hedonistic abandon to the tantalizing rhythm of samba. Its Carnival in Rio de Janeiro, and samba permeates virtually every aspect of the festivities, as it has for much of the past century.

Rising out of the rhythms of African slaves, samba crystallized as a distinct musical form in the 1920s. A decade later, musical groups organized as escolas de samba (samba schools) were regular participants in Carnival parades.

"Today, the most famous part of the Carnival in Rio is the big samba school parade," says Chris McGowan, author of The Brazilian Sound (Temple University Press, 1998). "Its an incredible spectacle. It dwarfs anything else on the planet."

Lest you think McGowan indulges in hyperbole, imagine a marching band with more than 5,000 members. That's the number of elaborately costumed sambistas a single escola de samba can bring together for its 90-minutes in the sun, parading through the prestigious Sombódromo or along one of the lesser known routes.

The beat goes on

Despite their name, Rio's escolas de samba function more as social clubs than schools. Neighborhood escolas have become important cultural institutions, and many escola members will tell you that samba is not only a musical form or dance, its a way of life.

The heartbeat of every escola is the bateria, the percussion orchestra. Often 300-members strong, it may comprise more than a dozen percussion instruments, including surdos (booming drums played with the hand and a mallet); caixas (thin snare drums); tamborims (tamborine-sized drums played with a wooden beater); cuicas (friction drums played by rubbing a stick protruding from the drum head with a damp cloth); agogos (tuned cow bells played with a stick); and pandeiros (tamborine-like instruments with a "dryer" sound).

Baterias typically strive to develop their own unique sound. Some school's baterias, for instance, are recognized for emphasizing a certain beat; others are distinguished by their mix of instruments. Whatever their musical approach, the bateria percussionists must practice hundreds of hours to acquire perfect synchronization, both with each other and with the singers of the samba-enredo, the original theme song each escola commissions for the parade.

"The songs are often something historical or political, with very meaningful, sophisticated lyrics," says McGowan. The tone, however, is far from lyrical. As McGowan points out, the singing combined with the percussion creates "a big wave of sound. The samba the samba schools play is really thundering."

A kinder, gentler samba

Of course, not all samba originates on or is suitable for the parade grounds. In fact, in Rio's nightclubs, you're more likely to hear samba-canção, a softer, slower, more romantic samba; pagode samba, a scaled-down, less orchestrated style of samba; and, of course, bossa nova, the "new style samba which combines simplified samba rhythms with complex harmonies for a more jazzy sound.

You don't have to trek to Rio to hear the sounds of samba and bossa nova. Today, bossa nova is a permanent subset of American jazz, and samba schools can be found in Los Angeles, Helsinki, and even Tokyo.