The documentary “1991: The Year Punk Broke” followed Sonic Youth, Dinosaur Jr., Nirvana and other bands as they toured Europe—but the title of the film didn’t even begin to cover what really broke through that year. Grunge was the buzzword, but looking back it’s remarkable to hear how little Nirvana, Pearl Jam and Soundgarden had in common beyond provenance (Seattle), clothing choices (flannel) and big, loud guitars and drums (albeit informed by different influences: punk, classic rock, metal). It was the year that “alternative” really became not just a category of music but a cultural identity.

Suddenly, the hair metal and dance pop that had dominated the Top 40 charts sounded like the last whimper of the dinosaurs. And R.E.M., a band that had been around for a decade, sounded as fresh as ever as they broke through to the mainstream and even people who had once made fun of them suddenly found themselves singing along to "Losing My Religion." My Bloody Valentine created a shoegazing masterpiece of noise that would influence countless bands, as would Dinosaur Jr. and the Pixies with their oddball signatures. Smashing Pumpkins and Hole both gave us the first glimpse of their future stardom. And it wasn't just the year that alternative rock broke big. There was the dominance of alternative hip-hop, too, as A Tribe Called Quest bucked gangsta rap posturing to focus on social consciousness and a style that easily melded hip-hop and jazz, setting a template that would forge a whole new byway for the genre.

Nirvana - Nevermind

At this point, to talk about Nirvana's influence on modern music is a bit like talking about that of The Beatles: It's pervasive. It's also hard to overestimate the dramatic and almost instant shift that the band had on pop culture in 1991. When Nevermind, their major-label debut, was released—and, especially, the song and video for "Smells Like Teen Spirit"—it was like a generation woke up. Within a couple of months, the album was a hit, people were dressing in "grunge" flannel and, soon, hair metal was dropping off the charts. (The band's feminist attitude was also a welcome change from the blatant sexism of hair metal.) Cobain's aesthetic was very much a Gen X product of what was then known as college rock and would soon be categorized as alt rock, with an entire radio station format dedicated to the movement that Nirvana pushed into the mainstream. It seems perverse now to lump Nirvana with, say, the metal and classic rock leanings of other bands that were considered grunge—Pearl Jam, Alice in Chains, Soundgarden. While Nirvana's style was revolutionary, it's easy to track the band's roots to its contemporaries: the melodies of R.E.M. and The Vaselines, the jagged snarl of bands like the Melvins, the dissonance of Sonic Youth, the distortion of Mudhoney and the loud-soft dynamics and pretty-weird melodies of the Pixies (well illustrated in songs like "Lithium"). New drummer Dave Grohl's hardcore punk background power-charged things ("In Bloom" "Territorial Pissings"). Cobain's ragged voice and distorted guitar (a variety of Fenders, including a Mustang, a Jaguar and Stratocasters) would define the era. Almost immediately, Nevermind spawned shameless imitators like Silverchair and Bush, while bands such as Weezer and Dandy Warhols would embrace Nirvana's inspiration and reinterpret it. Longterm, you can hear Nirvana's influence on the disparate likes of Wavves, Muse, 30 Seconds to Mars, Sturgill Simpson, Courtney Barnett and Machine Gun Kelly.

Pixies - Trompe le Monde

Within college radio, the Pixies were already beloved by 1991; Kurt Cobain called them a major influence on Nirvana and the band's masterful use of soft-to-loud dynamics was co-opted by the grunge scene. But Trompe le Monde, the Boston quartet's fourth full-length album, made the band into royalty. It's loaded with surf rock riffs, spacey sci-fi moments and candy-coated weirdness—and that's just one song, the wonderful "Alec Eiffel." There's also Sam the Sham-style garage rock ("U-Mass"), beautifully soaring noisemakers ("Bird Dream of the Olympus Mons" and the title track) and punk-metal goofs that turn into heaven-bound glory ("The Sad Punk"). Their pep-pill cover of Jesus and Mary Chain's "Head On" is a loving tribute that may just best the original. You can hear Pixies' sweet-and-gnarly dynamics and waves-against-the-rocks majesty in music from the likes of PJ Harvey, The Strokes, Modest Mouse, Cage the Elephant and, more recently, Wolf Alice and Savages. Weezer owes Pixies a debt for figuring out how to borrow from metal without it seeming like a joke. No less than Radiohead have cited them as an influence. The Pixies' last hurrah before bassist Kim Deal formally ditched to form The Breeders and the band called it quits for a decade, Trompe le Monde stands as a time capsule of '90s influence.