In 1991, Kurt Cobain, the Nirvana frontman who died thirty years ago this month, wrote a letter to Rolling Stone, expressing what he thought about the magazine’s audience and political pedigree. “At this point in our, uh, career, before hair loss treatment and bad credit, I’ve decided I have no desire to do an interview,” Cobain wrote. “We wouldn’t benefit from an interview because the average Rolling Stone reader is a middle-aged ex-hippie turned hippiecrite, who embraces the past as ‘the glory days’ and has a kinder, gentler, more adult approach toward the new liberal conservatism. The average Rolling Stone reader has always gathered moss.”

Cobain’s letter was never sent. He and the other members of Nirvana — Krist Novoselic (bass) and Dave Grohl (drums) — eventually agreed to appear in Rolling Stone, albeit with Cobain famously wearing a T-shirt emblazoned with “Corporate Magazines Still Suck” on the cover. Nevertheless, this letter, which is excerpted in Charles R. Cross’s excellent biography of Cobain, Heavier Than Heaven (2001), captures the acerbic political sensibility of the singer-songwriter — a spirit that has often been minimized by critics and lost among listeners of his music.

Class rage is, fundamentally, the rage found across Nirvana’s studio albums. From their debut, Bleach (1989), to their swansong, In Utero (1993), the sound and attitude of Cobain’s music was deeply rooted in his working-class background, which centered on the logging town of Aberdeen, Washington, where he lived for most of his abbreviated life. His lyrics rarely addressed this context directly. But his worldview and critical perspective were vitally shaped by the lumber economy, wealth inequality, and subsequent lack of middle-class opportunities he experienced growing up in a small town in the Pacific Northwest.