Few musicians take as much unfettered glee in the sheer act of performance as Jonathan Richman. At the First Unitarian Church on Sunday night, Richman frequently stepped away from the microphone and put down his guitar to dance. As his body twisted and bucked (the crowd was particularly fond of his sweeping high kicks), his eyes were wide and distant, as if he'd been swept away by his own songs.

Richman, 57, is best known for the albums he made with Boston's Modern Lovers, particularly their self-titled 1976 debut, which married brute garage rock to Richman's naive romanticism. But like Big Star's Alex Chilton, Richman has since abandoned his early material along with most of the rock idiom, restyling himself as a modern troubadour. (In which guise he also appears in the 1998 movie

There's Something About Mary

.)

Although he still proclaims his affinity for the Velvet Underground, Richman these days is more Hoagy Carmichael than Lou Reed.

The lineup for Richman's live shows is as simple as it gets: Richman himself on nylon-stringed acoustic guitar, and drummer Tommy Larkins, whose main job is keeping up with Richman's relentlessly shifting attentions.

More than once, Richman started a song's verse only to abandon it after a word or two, requesting instead that Larkins "talk to them on the drums." Richman danced around the stage, occasionally grabbing a cowbell to play along, like a child picking up toys in a nursery.

Although his enthusiasm is childlike, Richman's lyrics can be wistful, even melancholy. On his new album,

Because Her Beauty Is Raw and Wild

, he retools the Modern Lovers' "Old World," transforming it from a tribute to vintage Americana to a eulogy for it. "As My Mother Lay Lying," which brought the show to a hushed close, is a delicate air set at his dying mother's bedside.

Although he has his qualms with the modern world, Richman's music is a celebration of the moment, which in "Es Como El Pan" he argues should be as fresh as newly baked bread. (Showing his old world allegiance, Richman sings in a number of European languages, including Spanish, French and Italian.)

"You Can Have a Cell Phone That's OK But Not Me" and the anti-antidepressant anthem "When We Refuse to Suffer" take aim at modern conveniences that insulate us from the real world. (The former, naturally, is available only as old-fashioned vinyl 7-inch single).

The defining song of Richman's solo career, "I Was Dancing in the Lesbian Bar," brought the crowd to its feet, joining his celebration of accepting joy wherever you find it. In a way, the concert's setting, in the church sanctuary, was apropos. There's something about the purity of Richman's delight that seems strangely close to a state of grace.