Did the late 1990s represent a backlash when it came to gender, or a necessary move toward the center? There's still disagreement on this point. But most pop historians would agree to mark the turning point with the platform-sandal footprint of the Spice Girls. Glittering the landscape in 1996, the English quintet seemed to embody a flighty femininity that the time's fierce zeitgeist-rulers, like Polly Jean Harvey or Queen Latifah, actively opposed. Yet the Spice Girls' career-setting anthem "Wannabe" giddily leapt ahead of its time: I vividly remember hearing it for the first time in an English hotel room, bubbling out of the television like an exploding packet of Pop Rocks spit out by these cute but absolutely normal-looking girls rampaging through a fantastical nightclub. They were yelling about women's friendship! They kissed the boys and just kept on going! One of them was jogging pants and a sports bra! I was a devotee of the time's most confrontational rock and hip-hop, but there was something to this idea that women's solidarity wasn't just for the boldest and the most bohemian.

The Spice Girls were outliers, but not by much. Their massive popularity presaged a new wave of American teen pop also spearheaded by a tricky sweetheart: Britney Spears. Today, Britney has become a first-name-only goddess revered by dance music mavens for her willingness to take chances with experimental producers while still owning the center of the pop charts. As a feminist icon, Spears remains nearly as problematic in 2018 as she was when her authentic schoolgirl pout made her a star with "...Baby One More Time" twenty years earlier. She's still one of the most powerfully charismatic pop stars of our age, and deserves respect not only for being the indelible voice of a pop juggernaut, but for her longevity in the face of every major pitfall celebrity can create. Yet since a public breakdown made her an official pop tragedy in 2008, a debate has raged about whether Spears has been the prime agent in her own success, or an exploited asset, and she herself is only now emerging as an artist in ways that might clarify matters. The story of Britney Spears couldn't have been less suited to the story of women toppling male power structures that dominated the 1990s. Nonetheless, her importance as both a musical and cultural influence is undeniable. Like Elvis, Britney Spears embodies a seismic shift in American culture – not toward the cultivated rawness of rock and roll, but away from it, into an era dominated by new technologies that throw into question the very nature of the authentic. A voice in league with new technologies, Britney Spears embodies something fundamental about our time. Every artist working in the pop realm reckons with her.

The troubled iconicity of Britney Spears can overshadow just how much other women changed popular music just before and after her emergence. Before her, there was Gwen Stefani, who like every cool kid's favorite Spice Girl Mel C decked herself out in clothes as sports-functional as they were sexy, and who sang about the very limits placed upon her as a woman fronting an all-male band in No Doubt's "Just a Girl." (Stefani, like a few others who debuted in the 1990s, makes our list because her solo career commenced in earnest in the 2000s.) There was Jewel, singing about addiction and the the sexual exploitation of young women in a hit, "Who Will Save Your Soul," that critics dismissed as teenage flowered-notebook rambling. A year later there was Fiona Apple, who made her revelations about sexual trauma and its aftermath — her song "Sullen Girl" was a #metoo moment decades before its hashtag — but whose very (slender) physique seemed out of step with the time's feminist mores. "I'm a little torn," sang Australian pop star Natalie Imbruglia in 1998, her baggy hoodie in the "Torn" video sending one message while her glam squad-enhanced eyes sent another. It was hard, sometimes, to tell whether these ingenues were sending mixed messages or signaling complexity. Something similar was happening in R&B, as the mighty TLC led a new wave of sleek-voiced women whose versions of empowerment weren't as obviously fierce as what En Vogue had embodied in 1992's "Free Your Mind."

Could women's empowerment creep into patriarchy's engine, dismantling the status quo in other ways? The girl-group renaissance ushered in by TLC and moved forward by solo artists like Brandy, Mya and Monica showed ways that this could happen. At the same time, Missy Elliott and Aaliyah were shifting the very ground of R&B, creating an intuitively feminine and de facto feminist language within it via deft samples, new ways of singing and lyrics that sometimes sounded like but never really were nonsense. These trendsetters were joined by Destiny's Child in 1998 – a group that would not only launch the career of the new millennium's musical empress, Beyoncé Knowles, but which would blend better than anyone else the classic soulwoman's mandate to talk smack to men's power with hip-hop's new approach to vocalizing and musical arrangement. (It's no surprise that Elliott is one of the producers on the group's landmark 1999 album The Writing's on the Wall.)

Some women on the cusp between the wild mid-1990s and the more choreographed 2000s focused not on confrontation, but on building points of view that could open up into whole worlds. Erykah Badu and Lauryn Hill set the gold standard for this approach, their songs honoring black women's realities even when they contradicted conventional ideas of women's liberation. Jennifer Lopez, who would later go on to be a pop force as powerful as any in the early-to-mid 2000s, forged a new path in Latin crossover pop by blending the Gucci glamor of '90s hip-hop with the street-smart energy of Latin freestyle and salsa.

The list of genre-shakers from this period continues, including enough legends that had NPR's list spanned a logical two decades instead of starting in 2000, the Top 10 could have easily featured 1998 and 1999 releases alone. (This is one reason we made 2000 our jumping-off point for this list: We wanted our voters to keep the present day in sharp focus, uninfluenced by nostalgia for this moment and its superstars.) In country, beyond the Dixie Chicks, Shania Twain — who was much more the architect of her own stardom than more early accounts, who credited her then-husband and producer Mutt Lang, acknowledged — changed the genre itself by giving voice not only to sexually assertive womanhood but to the rock and roll-loving suburban middle class that then constituted its audience just as much small towners.

Gillian Welch practically invented country's more artisanal offshoot, Americana, by reinvesting folk traditions with a remarkable clarity made possible by her outsider status. Coastal children who met as New England music students, she and her partner David Rawlings entered the roots music world unhindered close inheritance, and became the ideal revivalists of the Internet age — meticulous archival explorers who built their own sound world that wasn't a copy of the past but a means of letting it permeate the present: time travel as mindfulness practice. And in indie music, Neko Case — an artist who's gone on record about not wanting to be included in gender-based lists like Turning the Tables — set a new standard for songwriting by refusing the limits of genre, verse-chorus-verse and linear narrative, setting the tone imaginative inquiries later taken up by artistes like Joanna Newsom and The Decemberists.

Most of these women were misunderstood in their moment of emergence, or critically lauded but still undervalued as major innovators. (Badu and Hill are the exceptions, having answered the most serious problem within the 1990s feminist movement in popular music — the drastic need for perspectives from women of color.) In an early review I now regret, I myself mistook Welch and her partner David Rawlings as purveyors of tight-collared costume drama rather than interrogators of a folk lineage that deeply needed their intervention. Gen X music fans like me, who tasted the revolution on the lips of brazen iconoclasts like Kathleen Hanna of Bikini Kill, couldn't always see how the artists taking the decade into the future weren't abandoning the sweeping project of remaking popular music in the true shape of womanhood, but proving that this endeavor would not take one shape or be ruled by one sound, as much as so many of us loved the noisiness of our own cohort. A soft voice like that of the chanteuse Dido, whose 1999 debut No Angel became the second-best selling album of the 2000s in England, might have seem like a throwaway sweet, worth less than the meat we got from our favorite rockers or rappers. Yet that voice singing lyrics like, "I just want to feel safe in my own skin" feels as or more relevant now, with so many women saying the same thing within social media's danger zones.

It wasn't so long ago that other cusp eras like the early 1970s or the late 1980s were also disregarded as overly commercial or adrift within pop's larger historical sweep. Eclecticism and the kind of experimentation that moves incrementally can be mistaken as a kind of watering down of more openly provocative practices. History often unfolds in arcs, not because real life is that way, but because the storytellers who write it crave the dynamic narrative pull such structures provides. Some periods end up on the down side of the circle.

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