Bob Mould, the loud punk rocker, takes out a chainsaw and amputates the leg when the wound gets too aggravating. Bob Mould, the folkie with the 12-string guitar, picks at the scab until it makes him scream with anguish.

Either way, there's a lot of fuzzy, trebly noise and you can barely hear the words -- except for snippets, such as "there is nothing left at all," "swing by your neck on a vine" and "I couldn't begin to smile." Mould, the one-time lead singer of Husker Du and Sugar, used his solo acoustic act Saturday night to de-emphasize catchy pop melodies and magnify the lyrics' emotional power.

Mould sat alone in the dark, wearing a gray T-shirt and jeans, pounding and strumming his guitar like Pete Townshend endlessly caught in the beginning of "Pinball Wizard." At Chicago's sold-out Vic Theatre, where the few seats for clear listening were right up front, you could barely hear Mould's voice above the thumping chords. It was an hour-and-a-half ride into the dark.

Every now and then Mould offered release from the tension -- he joked with the audience, answered the crowd's shouted "How's New York?" questions with genuine friendliness and acted like fans were his friends. He also threw in, amid an avalanche of rawness and gloom, Sugar's small radio hit and almost-love-song "Your Favorite Thing." Its playful opening guitar riff, along with the upbeat melodies in "See a Little Light" and "If I Can't Change Your Mind," were welcome contrasts from the predominant heavy strumming.

It's tempting to lump Mould with Jackson Browne, Joni Mitchell or any of the self-confessional singer-songwriters who endlessly analyze their emotions. But Mould's punk bluntness rescues him from that dead end: "Roll Over and Die," a song he played from 1996's "Bob Mould," is about a broken relationship, but its key line is a harsh kiss-off.

Mould focused so little on the newer material that he was moved to apologize. "Thanks for being tolerant. But lately I've been feeling like I'm off the normal page," he said. "I better play something off the new record or I'm going to get dropped." Mould picked his short songs, often ending so abruptly you barely noticed that the next song had begun, from all corners of his prolific 10-year recording career. "If I Can't Change Your Mind," from Sugar's 1992 album "Copper Blue," for example, came before "Poison Years," from Mould's 1985 solo debut "Workbook."

This broad career approach showed how much Mould has grown as a singer. When Mould started with Husker Du, his voice was flat and monotone but full of personality; he has slowly figured out how to rise above his vocal limitations. On "Brosilia Crossed With Trenton," another of several songs he played from "Workbook," he began in his gravelly singing voice and finished with creepy blood-curdling shrieks.

During a second encore, he turned his 1986 Husker Du song "Too Far Down" into a countryish anthem -- although even George Jones might consider himself too happy to sing such lines as "the darkest hole is at the end of the road." Mould's inspiration comes from many sources, including Richard Thompson's guitar playing, Townshend's rocking self-analysis and country music's sadness wrapped in pop. What comes out is a barbed-but-exhilarating sound that Mo