Before the fire that almost consumed him three years ago, Richard Pryor used to joyfully exercise his demons in public. They materialized from the mean streetcorner as winos and junkies in irreverent soliloquies that confirmed Pryor's ear for the nuances of ghetto culture. The talk was dirty and behind every punchline there was a bittersweet truth about being black in America.

At Constitution Hall last night, Pryor turned to exorcising his demons. There was a subtle undercurrent of pain to much of his 80-minute performance, though he never crossed that thin line between confessing and preaching. Touching many bases--marriage, boxing (pal Sugar Ray Leonard was in the audience), white people, a visit to Africa, Chicago weather--Pryor seemed most sure of himself in the sexual arena, the site of many ribald campaigns over the years. His gestures broadened, his voice took on authority, his patter raced undisturbed from weaponry to battles to aftermaths.

Pryor also did a sharp bit based on his recent perceived presidential snubbing after a special showing of "Superman III": "I thought I had s--- on my shoe," Pryor said with genuine hurt. " He looked at me like I owed him money!" He added a few zingers that could easily have scalded First Family ears less than three blocks away.

When Pryor changed the topic to drugs and alcohol, however, his tone changed as well. A hesitancy crept in and he seemed distracted by his audience's expectations. Which is dangerous, because it's been Pryor's trenchant celebration of drugs and alcohol and his warm scatological delivery that have endeared him to millions. He was cheered when he said he had been off drugs for seven months ("I'm hangin' in there"), but he was cheered more loudly when he seemed to be slipping into familiar routines.

Except that he never really did. There was only one wino bit. Of the "freebasing" that almost killed him, Pryor said, "It's the best feeling in the world," adding, as the applause rose, "unless you want to be a human being." That garnered some uncomfortable applause.

There were other changes as well, and necessary evolutions. Last night, Pryor was mostly Pryor; there were few of the superbly defined "characters" of recent years. It's as if Pryor has had to move out of the old neighborhood on his way to that new $40 million film career, but there's little doubt he'll carry a lot of friends out as well. His vocal inflections remain superb and his face is a true wonder: The eyes sparkle with mischief and the enveloping Pryor smile is at once innocent and knowing. The harsher expressions are effective, but they seem so . . . temporary.

Pryor, who returns tonight, ended the show with a stunning piece of old-fashioned streetcorner theater, a soft-spun but searing junkie monologue that chillingly embraced anxiety and pain and sadness and dying. It was a signal that was widely misread; for all its insightful humor, it may also have been an elegy for a kind of comedy that is ending for its master.