BOSTON — There's more light in most rehearsal spaces than there was onstage at the Avalon Ballroom on Monday. But that was the vibe sought by Ryan Adams, who even chided the lighting guy at one point to keep the illumination dim.

Granted, there were passionate flashes of showmanship from the scruffy singer/songwriter, who is swinging from the alt-country underground into budding rock stardom with recent CD, Gold. But the most animated moment came when Adams abandoned his guitar to kick off an encore with the Rolling Stones' "Brown Sugar," a nod to the biggest influence on the scrappy rock that dominated his 100-minute show. The singer pranced with one hand behind his back and the other pointing high.

Elsewhere, though, Adams acted more like the sold-out crowd of 2,000 happened to be on hand for a well-honed rehearsal that just happened to begin with a modest opening set by girlfriend Leona Naess. He blended into the chunky fabric of his backing band, Sweetheart Revolution, a five-piece group akin to the Black Crowes, robustly singing with lonely conviction as his hair fell across his eyes.

"You can hear the heart in his music," said Josh Steinberg, 19, a Long Island-bred Emerson College student who waited five hours to get in front of the stage but expressed disappointment after the show. "You could see flashes of brilliance, and other times when he was completely self-indulgent. He was completely retreating from the audience."

Indiana native Tamzin Kennebrew, 21, who drove up from Brown University in Providence, Rhode Island, offered, "I think he's sort of surprised and flattered by all the attention he gets and doesn't know what to do with it."

Eschewing his sensitive, melancholic side, Adams rocked from the outset with "The Rescue Blues" (given a much rougher treatment than on Gold), "To Be Young (Is to Be Sad, Is to Be High)" and "Firecracker," before losing the Van Morrison inflections of "Answering Bell" by dropping that song into the middle of the Grateful Dead's somber "Wharf Rat."

After the more melodic shades of "Somehow, Someday" and "Touch, Feel & Lose," Adams and his band also slipped from the Stonesy honky-tonk of "Tina Toledo's Street Walkin' Blues" into a meandering jam iced by the lap steel strains of ex-Dylan sideman Bucky Baxter. And for the most part, the set list went out the window. "New York, New York" (a hit song about a girl who became a symbol for the city) went unplayed, and Adams stretched into the spacey, Doors-like folds of a new, largely ad-libbed song. "I don't f---ing care anymore," he sang in one refrain, then led the band through rocking set-closer "Nobody Girl," featuring searing guitar leads from his onetime Whiskeytown mate Brad Rice.

Adams ended that number as he did the encore (another new song, the lurching riff-rocker "Vampire," in which he sang, "I'm a fake and I'm a liar") by dangling his guitar into feedback, letting it drop, then sauntering offstage.

"Dark and disturbing," fan Bill Carlezon, 35, of Boston said. "I loved the CD, but the concert was a different story. It's really all about him."

Read about all of the shows we've recently covered in Tour Reports.