Anyone who doubts that singers pose a real threat to a government should consider Victor Jara -- one of the first arrested by the Chilean army during the 1973 coup. When Chile's folk hero refused to stop singing in a stadium prison, the army reportedly tortured and killed him. Now Jara is a model for political artists around the world.

Peter, Paul and Mary and a Chilean folk group, Quilapayun, paid tribute to Jara and his example last night at the Kennedy Center. Obviously inspired by the occasion, the three American popularizers of protest music transcended their modest talents. The same songs that were embarrassingly nostalgic in last summer's reunion concert became immediately urgent last night. The group stuck to their best-known early songs with convincing vocals and precise harmonies.

Quilapayun, formed under Jara's direction in 1965, has been in exile since the coup. They had followed Jara's admonition to join Chile's rich Indian, Spanish and peasant folk traditions to personal and political lyrics. During Pablo Neruda's "The Americas" the seven Chileans played 15 different native instruments and sang seven-part harmony.

At times Quilapayun was an overly formal choir. The best moments came when the breathy sound of bamboo pipes and wood flutes swam above the lunging Latin rhythms.

Among the special guests -- including Isabel Letelier and Joan Jara, the singer's widow -- was Sen. George McGovern who paid tribute to Jara and the singer's heirs by admitting "the frailty of the spoken word compared to the power of these musical artists."