It is a question that has vexed philosophers, by which I mean people who perhaps overthink popular music, for 25 years now: Who is the real Beck?

Is sad Beck the real Beck? Is funky Beck the real Beck? Is Grammy-winning professional craftsman Beck the real Beck? Is hip-hop addled junk culture vulture the real Beck? Is somewhat corny, crowd-pleasing Beck the real Beck? Are all of them the real Beck? Are none of them the real Beck? Is there a real Beck? Beck is Beck is Beck? Sprechen Sie Deutche Baby?

Beck Hansen has had one of the most interesting and singular career arcs of any musician of his generation, and his sixth album, Mutations, marked a turning point in a catalog filled with turning points. It is the album that solidified the idea that Beck is prone to do whatever he wants. Is it also possible this is where we first saw a glimpse of the real Beck, and therefore every time he was chasing down some sort of impulse, the expectation is that this is the mean to which he would inevitably return. Maybe. It is also possible that “real Beck” is yet another guise this chameleon of a performer decided to put on, in the process making us question if “real” really means anything at all.

By 1998, Beck was in the rare position of being both unimpeachably cool and absolutely huge. His 1996 everything-at-once album Odelay was an era-defining smash. He lodged alt-rock radio hits in an era where that still mattered, performed at the Grammys, losing Album Of The Year to Celine Dion. He swept the 1996 Village Voice Pazz & Jop Awards, made the cover of Rolling Stone, and was named the Most Important Artist In Music by Spin. He had become such a shorthand for “Smart But Accessible Alt-Culture Figure” that MillerCoors even shamelessly ripped off his whole steez for a beer campaign based around a slacker character named Dick.

Of course, no one stays in their imperial period forever, and one can only imagine how Beck felt, watching as the wildly free-flowing sound he and the Dust Brothers created on Odelay was immediately turned into frat-boy fodder by the likes of Smash Mouth and Sugar Ray. So with Mutations — which turns 20 tomorrow — he made a hard pivot, setting aside his free-associative hip-hop sensibilities for a series of cosmic folk songs that saw him trading Irony for Feelings.

After the tour for Odelay wound down, Beck recruited Nigel Godrich for his major work after helming Radiohead’s OK Computer, the other huge era-defining alt-rock album of the late ’90s. Beck and his crack live band cut a song a day for 14 days, for an off-the-cuff feel that Godrich would soak in his trademark antiseptic, Kubrikian sheen. The original plan was that Bong Load Records, the tiny Los Angeles label that first released Beck’s breakout “Loser” would also release Mutations.

Beck had worked out an unprecedented deal with Geffen Records that would allow him, in theory, to release albums with smaller labels, which is how K Records was able to release his collection of early lo-fi recordings One Foot In The Grave and Flipside released his hodgepodge Stereopathetic Soulmanure the same year as Geffen released his official debut Mellow Gold. But after hearing Mutations, Geffen pulled rank and insisted on releasing the album, marketing it as a detour for hardcore Beck fans while he stayed hard at work on the “real” follow-up to Odelay. No videos were made for the album, and aside from appearing on Saturday Night Live, Beck did little to promote it, but such was his stature at the time that the album eventually went platinum and won Best Alternative Music Album Grammy.

I get the sense that amongst critics and fans, Mutations is often considered Beck’s dress rehearsal for his 2002 heartbreaker Sea Change, trying sadness on for size before later going Full Desolation. But honestly, this is probably because of the album highlight “Nobody’s Fault But My Own,” which finds Beck beating himself up over unspecified mistakes over a sea of psychedelic strings that could have been sampled from Rubber Soul. It was a startling turn at the time, the effortlessly cool guy from “Where It’s At” asking aloud, “Pointing a finger, throw the book at you/ And who would want to dance with you?”

But listening to Mutations today, I think what the album tells us is that even when he’s trying to be serious, Beck is still a playful guy. “Cancelled Check” and “Bottle Of Blues” have a light, Hank Williams-worthy sway to them, complete with some light piano rolls on the former; you can practically see Beck copping a sheepish grin while tinkling the ivories at a frontier barroom for a bunch of prospectors during happy hour. “O Maria” might revolve around an oddly moving couplet that signifies the need to grow up already (“Everybody knows/ the circus is closed”) but it glides by on a ’60s melody that feels cloned from Donovan.

There’s enough fingerprints of classic rock songwriters, from the Lennon-ish melodies and chord changes on “Dead Melodies” through the Bob Dylan worthy whines of “Lazy Flies” that it sometimes feels like Beck’s aim was to make an album that if you found it in a dusty vinyl pile, you might mistake as a lost prize from the ’60s, à la Inside Dave Van Ronk. But while Beck is a scholar of music, he’s never been content with merely reproducing his record collection. Mutations is filled with dozens of tiny little Beckisms, choices only he would make, be it contrasting a wheezing harmonica with sci-fi synth wiggles on “Cold Brains,” undercutting the Beatles-like reverie of “We Live Again” with dread-inducing negative space or spicing his Brazilian-music homage “Tropicalia” with post-modern lyrics about isolation and a noisy sound collage.

Mutations would prove that Beck could do sincerity, or at least Sincerity, just fine thank you very much, and the woozy, operatic country rock he summons here in many ways feels like a blueprint that Mike Mogis and Conor Oberst would follow with Bright Eyes, where the slowly unraveling ballad “Static,” tucked all the way at the end of the album, feels like Beck’s big budget answer to the delicate balladry Cat Power and Elliott Smith were getting up to, declaring “it’s a perfect day to lock yourself inside” as the guitar solo shrugs and the keyboard lines evaporates.

After this album, Beck would release Midnite Vultures, a gloriously daffy R&B party starter that Beck apparently thinks people hate but that many people consider his best. He would follow that up with Sea Change, the Serious Album that many other people would consider his true masterpiece. The gulf between those two says a lot about Beck (and also about what some critics like to champion, but that’s a discussion for another day), but its also what makes him so hard to pin down. Which is the real Beck?

But maybe that is the wrong question. Why should we think that writing songs about being horny and wanting to dance are any less valid than songs about watching your relationship fall apart? Why are ruminations on why guilt is both comforting and self-defeating any more or less valid than riffing on pop culture over the sickest drum break you can afford to sample?

It is possible that Beck knows when he sings in a strained falsetto about wanting to nail your sister, he knows he’ll get a laugh, and that he knows when he sings in a resigned lower register about feeling “unmoved, untouched, unglued” in “Cold Brains,” he knows he’ll get a sigh of recognition from anyone that has ever felt sad and unmoored (which is to say, anyone), and he’s a skillful enough performer that he knows how to hit both marks. Maybe it’s all just a guise to him. Or maybe Beck is telling you who he is every time he hits the microphone, and if he contradicts himself each time, if he’s telling you that he’s the heartbroken kid and also the goofy dad and also the sex freak and also the guy worried about the end of the world and also the guy who just wants to make you dance, then that’s how we know we can believe him. The truest thing about Beck is that he is whoever you need him to be. He’ll never give you all of himself but he’ll give you whatever you need.