"Let's face it. It stinks!" Joan Baez proclaimed, "it" being the world, of course. "Optimism is foolish," she added as a footnote. She then proceeded with a lovely ballad that was neither optimistic nor foolish, her crystalline voice gliding among the potted palms assembled on stage.

It was the quintessential Baez -- a captivating singer who is still contentious after all these years.

Her performance, before a capacity crowd at the Warner Theatre Saturday night, was a thoroughly entertaining affair, filled with politics, protests, new songs and oldies.

"Entertaining" is the proper word here. Depending on one's political sensibilities, Baez is either dead serious or a refugee from a Billy Jack movie. But her character, her idealism, is part and parcel of her stage persona -- what her admirers come to see -- and she obliged with strident monologues about her recent tour of South America, human rights, oppressed masses and the '60s.

And the music? There were frivolous ditties about growing old (or up?) and Princess Diana, several Latin American and Russian protest songs, selections by Paul Simon, Dylan and the Beatles, and Baez classics such as "Diamonds and Rust." Accompanying herself on guitar, Baez held forth with the high quivering, luscious vocals that have marked her as one of the more distinctive song stylists of her generation. As usual, her voice was both an amazing and saving grace that somehow managed to override the soppier sentiments.