Mariah Carey pranced through a slow-motion trainwreck in Times Square last New Year’s Eve and there was neither shock nor disappointment. Her instrument has been notoriously temperamental for well over a decade in the best possible conditions, let alone live on stage in the December cold. Her short setlist was ambitious at best and begging for trouble at worst. Laid low by technical problems, a failure to prepare, or some combination of the two, she tried to remain a good sport. She probably never should’ve taken the gig, though Carey’s career has been characterized by desperation and mismanagement for much of this decade, and she’d been reduced to hawking failed buzz singles and C-grade reality shows well before self-destructing in front of millions of viewers.

No matter how she got there, Carey found herself in an ignominious position for one of the greatest pop stars of the last 30 years. She’s sold enough albums to afford a new chaise longue every day until the sun burns out; when “Despacito” finally fell out of the No. 1 spot on the Billboard Hot 100 this summer after 16 consecutive weeks, it had only just managed to tie a record Carey and Boyz II Men set two decades ago with “One Sweet Day.” She may reject being called the “queen of Christmas,” but it’s a title she earned by co-writing the greatest contemporary holiday song in “All I Want for Christmas is You.” Her biggest hits have cumulatively spent well over a year on top of the charts. Her dominance gave her the reach she needed to become the most influential pop vocalist and writer of her generation.

The critic Sasha Frere-Jones outlined the two linchpins of Mariah’s legacy in an astute 2006 piece in The New Yorker, published after she defibrillated her career with the release of “We Belong Together.” Frere-Jones called Carey’s 1990 debut single “Vision of Love” the “Magna Carta of melisma,” and while its influence has finally started to wane, it remains the gold standard for pop stars who care about the craft of singing. You can hear her ghost in Adele and Sam Smith, in Bruno Mars and Demi Lovato. It took Carey three and a half minutes to lay down the terms by which pop virtuosity is still defined: power, range, and versatility, all of which she possessed for the first decade of her career.

Her second stroke of genius was ultimately more impactful. Carey did more than any other artist to bridge the gap that once separated traditional pop and hip-hop and R&B. She fused genres and sounds that were otherwise distinct, encouraging future artists to find and meet her somewhere in the middle. The aftereffects trickled down through the teen-pop icons and R&B crossover acts of the late ’90s to the stars shaping contemporary music: Beyoncé, Kanye West, Drake. (And Claire Boucher, of course: “The first time I heard Mariah Carey it shattered the fabric of my existence and I started Grimes.”) When Taylor Swift taps Future and Ed Sheeran for a posse cut and Rihanna hops on a N.E.R.D. single to rap alongside Pharrell, they’re walking a trail Mariah helped blaze. Her fifth studio album, 1995’s Daydream, played host to some of her purest pop songcraft, but it also pushed the boundaries defining what a Mariah Carey song was supposed to sound like.

In retrospect, Carey’s omnivorousness was hiding in plain sight: she’d gotten Carole King and members of C+C Music Factory to share space on the tracklist of 1991’s Emotions, and her ebullient 1993 smash “Dreamlover” sampled Stax-era soul via Big Daddy Kane. She had the diverse listening tastes you’d expect from someone who grew up in and around New York City with a classically trained opera singer for a mother and a black Venezuelan father. (”I’d get home from school, and she would have, like, five friends over who were jazz musicians,” Carey told Vibe in 1996, “and I’d end up singing ’My Funny Valentine’ at two in the morning.”) The album version of “Fantasy” would’ve represented another step towards the sound of hip-hop on its own: sampling Tom Tom Club’s “Genius of Love” lent the song a laid-back bounce that wasn’t too far from G-funk.

And yet everyone other than Mariah was still shocked when Carey worked with Puffy Combs and Ol’ Dirty Bastard on the “Fantasy” remix. Her label wasn’t exactly psyched: “Everyone was like ’What, are you crazy?’,” Carey told Entertainment Weekly in 1997. “They’re very nervous about breaking the formula. It works to have me sing a ballad on stage in a long dress with my hair up.” Puffy couldn’t believe it either: it “bugged [him] out” when she asked to work with O.D.B. “She talked about Wu-Tang and Notorious B.I.G. and Mobb Deep—everybody who’s hot,” Combs told Vibe in 1996. “It was like talking to one of my friends.” The surprise in his voice is palpable, even on the page.

Carey was the only one with the vision, and it paid off: the “Fantasy” remix is still lean and cool, like one of those Nestea commercials where beautiful people fall backwards into interdimensional pools when they take a swig. By stripping the original “Fantasy” down to its skeleton, Puffy created space to appreciate Mariah’s complex vocal runs; O.D.B.’s ragged, comic energy is the perfect contrast to her adolescent dreaming. Hearing it now, it’s one of those songs where you can imagine pop shifting in real time as it plays. And Carey knows she had the last laugh: “They laughed at me at the label when I played them my ’Fantasy’ remix with Ol’ Dirty Bastard,” she told Rolling Stone in 2006. “But you can’t explain to someone who didn’t grow up on hip-hop and who’s wanting to listen to the GoodFellas soundtrack exclusively that this is hot and it will be a classic.”

Daydream is at its most satisfying when Carey directly interfaces with R&B and hip-hop. “Underneath the Stars” is a tribute to ’70s R&B legends like Minnie Riperton complete with vinyl crackle, and it’s a display of the subtlety Carey’s detractors liked to claim she lacked. Gliding over a glistening Rhodes organ, she remembers an easy young love that slipped away. Lying with her lover on a warm summer night, she’s “a bundle of butterflies/Flushed with the heat of desire.” This is recurring imagery in the Carey discography, but it’s never rendered with more finesse than it is here. The accompanying vocal arrangement is delicate and imaginative; her whistle register is a garnish, not the main course. The final product is one of her greatest hidden gems.

She dipped into the opposite end of her range for “Melt Away,” a syrupy collaboration with Babyface that sounds like it could’ve been written for Toni Braxton. Carey’s voice is so rich during the song’s first verse that it tripped up some listeners: “A lot of people who wrote about the album thought that was Babyface singing at the beginning,” she laughed to Vibe. She’d come to lean on the sultry bottom half of her range as time and age made it tougher to reach the stratosphere, and “Melt Away” makes for an elegant early proof of concept.

Daydream also marked the start of Carey’s long, fruitful working relationship with the producer Jermaine Dupri. While the buoyant “Always Be My Baby” was a bigger hit—it was the third and final Daydream single to reach No. 1—it’s album cut “Long Ago” that now sounds like the shape of things to come. The songs have similar bones: there are moments in each where all you hear is Mariah singing over rock-solid piano chords, and the simplicity is almost surprising given her taste for the ostentatious. But “Long Ago” weds those chords to a rugged beat, and Mariah flows over it with the ease of someone with a genuine appreciation for hip-hop. (She could’ve gone even rougher: “I remember the first track we tried to do, she wanted to sing over Wu-Tang’s “C.R.E.A.M.,” Dupri told Genius last year.) Carey made this seamless blend of pop and hip-hop the core of Butterfly, and it served as the foundation for her late-career reinvigoration nearly a decade later.

Daydream is still interesting when Carey isn’t breaking new stylistic ground. She may have been showing off a newfound versatility on “Long Ago” and “Melt Away,” but she was also still near the peak of her powers as an athletic vocalist, and she put that athleticism to work powering daring arrangements and stunning modulations. “One Sweet Day” may be built around a killer hook, but that’s not what sticks with you on repeated listens—it’s the song’s ecstatic second half, in which Carey and Boyz II Men use that sturdy chorus as the foundation for gymnastic riffs and clusters of harmony. It’s not just showmanship, it’s an expression of communal grief that transcends lyrics and musical structure. (Carey wanted to write a eulogy after the producer David Cole, a collaborator and close friend, passed away in early 1995.) Their performance transforms an elegy into something joyous, a celebration of life and whatever might unite us after it. And while no other song on Daydream can match the emotive power of “One Sweet Day,” Mariah’s performances are uniformly strong no matter the context. “I Am Free” is a gospel workout, complete with an organ and the support of a mini-Mariah choir; dewy weeper “When I Saw You” is rescued by her melismatic belting; Ariana Grande would eat her ponytail for a ’50s waltz as potent as “Forever.”

The only Daydream ballad that’s an unequivocal failure is Carey’s cover of “Open Arms,” and that’s in part because it lacked Mariah’s pen. Carey came into her own as a writer on Daydream: she showed off her fabled vocabulary without leaning on the self-aware quirk of her later work, and almost every song is bolstered by at least one stunning piece of imagery. “When I Saw You” opens with a description of a lover that takes on cosmic significance: “Soft, heavenly eyes gazed into me/Transcending space and time.” (She touches on the power of “dawn’s ribbon of light” in the second verse.) The bridge of “Melt Away” opens with a “cloud of reverie” and ends with Mariah “rhapsodizing.” And she describes the love she feels throughout “Underneath the Stars” as “so heady and sublime,” a phrase that also happens to describe Carey’s lyrical stylings.

Daydream wasn’t just transitional in a musical sense. We know now that it was the beginning of the end for Mariah’s innocence, a moment that has some gravity given we’re talking about a star who likes to refer to herself as “eternally 12.” Her marriage to former Sony Music chief Tommy Mottola was crumbling, and she would look back on their relationship later and reflect on how it was governed by abuse and control. She didn’t know it then, but her absolute commercial zenith would soon be in the rear-view mirror. The instability of Rainbow and the full-blown breakdown of Glitter weren’t far away. Only closer “Looking In” hints at the darkness looming on the horizon: “She smiles through a thousand tears/And harbors adolescent fears/She dreams of all that she can never be.” It’s a startling final statement, but you still leave Daydream with effervescence in mind—sweet, stirring, and dominant, a tour de force from one of the greats at the top of her game.