Tom Petty played a game of "Who Do You Trust?" with a large crowd at the Merriweather Post Pavilion Monday night. When he shouted out "Ronald Reagan" and "George Bush," a chorus of "no" rained down on him. Then he mentioned Oliver North and was greeted by a mixture of "yes" and "no." Thus answered, Petty led his band, the Heartbreakers, through a blistering version of the Buffalo Springfield's great government-paranoia song, "For What It's Worth." That Petty is now willing to challenge his audience instead of merely pandering to it is just one indication of how he has matured as an artist.

Another indication is the way his lustrous folk-rock songs like "Here Comes My Girl" and "The Waiting" contained a new, gritty undercurrent, suggesting that the songs' hopes are not so easily realized. It also helped that Petty has kept his sextet together long enough that it plays like a single animal; everything from Mike Campbell's counterpoint guitar fills to Howie Epstein's high harmony vocals served the needs of the songs. It further helped that Petty has evolved into a real singer, one who convincingly expressed a mixture of regret, affection and bewilderment on the best of his new songs, "Runaway Trains."

Anyone who fondly remembers the days when the Rolling Stones were just a bunch of juvenile delinquents who loved a good joke would have enjoyed the Georgia Satellites' opening set. The Atlanta quartet began with songs by Chuck Berry and Bo Diddley played as loudly and as loosely as if they'd been manhandled by Blue Oyster Cult. The Satellites then proceeded to bang out a series of originals as clever as Berry's songs and as irresistibly lowbrow as any B.O.C. hit. Most impressively, these bar band veterans seemed to be having the time of their lives as they bantered, sweated and took the three-chord route to glory.