It's been 20 years now since the South African a cappella group Ladysmith Black Mambazo collaborated with Paul Simon, causing a sensation and creating controversy. More important, it's been 16 years since Nelson Mandela was freed, and Mambazo has continued to preach a spirit of national pride and reconciliation to audiences the world over.

Toward the end of Friday's McCarter Theater show in Princeton, when the seven-man group raised its fists in the air and sang "Nkosi sikelel' iAfrika," the South African national anthem, the spiritual and musical energy was palpable among the sold-out crowd.

Leader Joseph Shabalala brought a slimmed-down ensemble to the McCarter. Mixing the close, four-part, bass-heavy isicathamiya harmonies with South African boot dancing and the precursors of gospel, Mambazo breezed through traditional Zulu story songs, religious parables, and pop tunes such as "Homeless" and "Hello My Baby."

The group, together in various combinations for 45 years, was musically and choreographically tight and responded to the leader and each other instinctively. But there was also much room for individual personalities to come out.

Vusi Mahlasela, who opened for Ladysmith, brought the same spirit of national (and international) forgiveness to his performance. South African music, and its oral traditions, are full of hidden and shaded meanings, and Mahlasela masterfully conveyed these feelings despite singing in Zulu the majority of his show.

In a clear voice full of emotional range, he synthesized ironic, assertive and socially conscious traditional tunes and driving pop rhythms into a simple singer-songwriter formula.

After he had been singing for a bit less than an hour, Mahlasela, who sat for most of the show, exhorted the audience to clap and sing with him on "My Song Of Love."

Satisfied that folks had gotten his groove, he stood and began dancing with surprising, expressive grace. Then, smiling broadly, he shuffled offstage. A perfect way to end the segment.

-Kevin L. Carter