No one listens to Sonic Youth to learn about the personal lives of its members. The New York quartet are an ideas band—you listen to wallow in their famously retuned guitars, which nearly three decades ago altered rock's sonic palette as decisively as Hendrix had, and which are now a comfort staple to rock fans that can do without Hinder, thank you very much. Up till now you could also read about them without learning much about the members' backgrounds and private lives. This is odd, considering that Sonic Youth have provided one of the most prodigious paper trails in rock: countless reviews, interviews, and profiles, and a half-dozen books devoted to or prominently featuring them. But it's also appropriate: Thurston Moore, Lee Ranaldo, Kim Gordon, and Steve Shelley separate their lives from their careers; they leave the drama onstage and on record, where they belong. Even when they write lyrics about themselves (which is more often than you might guess), reading their catalog through the lens of autobiography seems superfluous.

That's why it's shocking to read the first chapter of David Browne's new Goodbye 20th Century: A Biography of Sonic Youth and discover 30 deeply reported, and often fascinating, pages on the early lives of Gordon and Moore, who formed the band early in their courtship and have been married since 1984. Browne conducted some 200 interviews, and for the book's first three quarters he organizes all that material into something shapely. If knowing all about Gordon or Moore or Ranaldo or Shelley's childhoods doesn't necessarily shed much light on their music, per se—the music stands up by itself—Browne's excavations are at least entertaining (Gordon's first high-school boyfriend was Danny Elfman, whose Simpsons theme song her band would later cover) and occasionally insightful. Browne brings up the fact that Gordon and Moore were both raised by academics a couple times too many, but that doesn't make it insignificant.

Browne bolsters the well-known facts of the band's rise with plenty of new material, the most priceless of which comes from composer Glenn Branca, whose early guitar ensembles included both Moore and Ranaldo, and whose alternate tunings inspired their band to adopt the same tactic. "Sonic Youth gave them what I had, but sugarcoated it," Branca tells Browne. "They knew I'd come up with all these incredibly cool sounds that could be used in the context of a rock song. At the time I wasn't going to do that... So I liked their candy-coated version of my music. I loved it. I came in my fucking pants."

And Browne is sharp on the band's move onto major labels: SY signed to Geffen, undergoing tense recording sessions for 1990's semistiff Goo and then nearly losing Ranaldo when one of his songs was rejected from 1992's expansive Dirty. That album came after one of SY's favorite younger bands, Nirvana, signed to the label as well, and released Nevermind. In its wake, Geffen began trying to groom Sonic Youth for genuine rock stardom—culminating with their headlining the 1995 Lollapalooza tour—even if the band itself largely thought the idea was a pipe dream. Browne is astute on the '90s rise of alt-rock: He quotes one anonymous business associate on SY's response to Nirvana's shocking multiplatinum success: "It was like having your baby brother suddenly become president." Still, it's hard not to get the sense that he might have been even happier to write a chronicle of the mid-'90s alt–gold rush, especially when he notes that over 100 modern-rock stations sprung up around the country in Nevermind's wake.

Unfortunately, Browne runs out of gas in the book's final quarter, even if he (rightly) doesn't think Sonic Youth's music does. Apart from September 11 (SY's rehearsal studios were located near the Twin Towers), the '00s are rushed through. He also ignores Amy Phillips's infamous Village Voice review of 2002's Murray Street ("Sonic Youth, please break up"). The page of outraged letters the paper ran a week later are all the proof anyone needs that among most of those who care, Sonic Youth are essentially bulletproof—more so than Browne's rushed litany of famous people whose careers received a boost through their association with SY. Despite these omissions, Browne smartly humanizes the most aloof of rock's great bands.