Fuji Rock Festival founder Masahiro Hidaka recently revealed that he wasn’t so hot on the whole 20th anniversary thing. ““I hate those kinds of things, so I didn’t want that on any of the banners. It was only after a month or so of their insistence that I broke and said, ‘Fine, let’s do the whole 20th anniversary thing then.’?” he told The Japan Times ahead of this year’s fest. It’s a funny revelation, especially after stepping foot in Naeba, where the vibe of this being a milestone happening permeates. It isn’t overbearing, but from the t-shirts to the special band sets to just how many people seem to have come out this year, it does feel very much central to these three days.

Beck’s headlining set Saturday night, though, felt like the official kick-off to the party. That was by design — the Los Angeles singer/songwriter appeared at the very first Fuji Rock Festival back in 1997 (and the next, not-stormed-out edition the following year). Partially, this was just historical reference, the fest bringing together acts who had appeared at the initial gathering (see also: Chili Peppers, Red Hot) as a nod to two decades of existence.

Yet with Beck, they also were partially paying tribute to the alternative music scene of the 1990s that allowed a gathering like Fuji Rock to spring up in the first place. Backed by a four-piece band, he opened the show with the familiar guitar riff propelling “Devil’s Haircut” feeling, the first song from his breakout album Odelay. The beginning and end of his set leaned on these moments, whether via the sax-assisted shuffle of “New Pollution” or dipping into R&B-glazed cuts such as “Sexx Laws” and “Mixed Bizness.” And, early on, he broke out “Loser,” the muffled-rap number that launched him, and when he hit the hook, the packed Green Stage audience bounced along and sang every word with him.

Sounds like a great chance to relive the ’90s, right? Well, in those instances, it was. But Beck has always been a restless artist, and he’s spun off in no shortage of directions after the arrival of the new millennium. What his set really highlighted was change — both for him as an artist and Fuji Rock as a gathering. The middle portion of his show leaned on sparse acoustic-guitar-guided songs primarily from downtrodden collections Sea Change and Morning Phase, while he also fitted in his most recent single “Dreams,” a chugging disco-tinged cut. Even the Odelay cuts underwent some changes — the samples that defined them on the recorded versions were toned down or removed, in favor of more guitar and drum, to give them extra punch live. Beck’s dancing meanwhile…well, OK, that was as awkward and charming as it always has been, as was a late set harmonica solo.

An anniversary is a chance to celebrate, but it can also illuminate all that has changed from then to now. This was a very different Beck than the one who graced the early Fuji Rock stages — he was more professional, more focused in, a bit more dad-like in his jokes (on “Debra,” he brought in new lyrics about the Japanese department store Parco). And Fuji Rock is a very different festival now too, bigger and full of more kids and featuring these chairs you kind of wear on your head while moving around the grounds. Yet there were moments, like on the fired up closer “Where It’s At,” where everything felt like a special throwback, the artist and audience both diving into the song like it was the mid ’90s again (with a breakdown paying tribute to David Bowie and Prince, to boot). And it was a feeling Beck even acknowledged during that final number.

“Twenty years can go by in a blink of an eye,” he said, perched on a speaker wearing a vanilla-white suit. “This is perfect weather, perfect setting. I could just sit here all night, no music.”