Mac McCaughan has always been a little more mature than the average indie-rock brat. In 1993, while Seattle bands swamped the charts with morbid, insular grumbling, his band Superchunk reached a smaller audience with its fourth and most powerful album, Foolish, a thorough autopsy of a failed love affair. Since Foolish, McCaughan and Superchunk have either been coasted or refined, depending on the point of view. The group has retained the explosive, punk-derived charge that made its reputation, but it often turns the volume down as well, supplementing its guitar assault with horns, strings, and organ. Superchunk's eighth disc, Here's To Shutting Up, opens with a case in point: "Late Century Dream" ambles along at a walking pace, accompanied by an irregular beat, a melodic organ buzz, and McCaughan's ruminations on the desire for personal property. "Rainy Streets" returns to the rushing tempos, live-wire guitar, and high, shouted choruses in which Superchunk has trafficked since the late '80s. There's something comforting about that pattern of balls-out rock alternated with mellower compositionsit's a rut, sure, but comfort with its own sound gives Superchunk the confidence to pull off a song like the nearly six-minute, multi-textured, airplanes-as-metaphor "Out On The Wing." And though the group hasn't recorded a song that burns with feverish intensity in about six years, it's developed an agility that few punks ever achieve, enabling it to give a stung-lover ballad like "Act Surprised" the proper balance of ache and anger. What hasn't changed is McCaughan's emotional expressionism, his ability to convey his feelings about love, work, and recreation with directness and hookiness. Superchunk may lack the gotta-hear-this spirit of youth, and it may never make a record that brings the rock world to its knees, but it presses on as a distinctive band of specialists, giving one sensitive man's thoughts a musical backing that bubbles humbly and attractively.