Last night, last night, last night! Dressed sharply in a fitted, light blue suit and navy polka dot shirt, Billy Corgan strode onstage at the Schnitz and ushered in the next era of the Smashing Pumpkins, his band of more than 25 years.

The 49-year-old singer—yep, Corgan is knocking on 50, people—strummed the opening chords of "Cardinal Rule" before a hand-painted backdrop featuring a row of cherry trees in full bloom, a kind of Japanese dreamscape. In case the set design didn’t make it clear, it quickly became apparent that those in attendance at the Schnitz for a straight rock concert would be leaving disappointed.

The Smashing Pumpkins' night in Portland was the first on their month-long, 19-city acoustic tour In Plainsong, an extension of last year’s tour under the same name, featuring wound-down versions of their discography. This all comes ahead of a planned studio stint to record a new album. The Pumpkins are back, it seems, and if the Schnitz was anything to go by last night, their fans never left.

It felt like the '90s all over again, as indie rock legend Liz Phair opened the show with her ho-hum, let’s-rock attitude—even though this was her first US tour in six years—and a smattering of well-placed profanities (the opening track was "Fuck and Run," after all).

And then—well, it didn’t feel like the '90s so much after all. The Corgan that appeared before Tuesday night’s crowd seemed light years away from the curly-haired, Chicagoan rock god to whom we were first introduced. As he calmly crooned "Tonight, Tonight," the crowd grew rowdier with every gently reworked lyric—downbeat be damned, this audience wanted to rock.

After several solo songs, guitarist Jeff Schroeder arrived, a newer addition to the Pumpkins lineup, having joined in 2007. The finer guitar interplays were lost upon fans more interested in whooping and hollering at every pluck. “Let me continue before you shout something weird,” Corgan demanded of an audience determined to relive some of the Pumpkins' riotous '90s shows. Sorry, folks: Billy had an agenda all his own.

Jimmy Chamberlain, the only other OG Pumpkins member onstage along with Corgan, emerged to a standing ovation as he settled down at the drum set. And once the full, five-person line-up was ready, the band launched into a setlist straight from 1993’s Siamese Dream.

Some of the songs strutted smartly in their new duds—in particular "Disarm," which Corgan played Phantom of the Opera-style, back turned as he pounded out a funereal organ line. Others never found their feet and left fans wondering if their hero had gone soft. “Put on a frickin’ show, Corgan!” the polite man seated in front of me offered up.

Thing is, it was a show, just not the show the fans expected. And with a new album due out, reportedly inspired by the sounds explored in these mellower live performances, it might be time to shed nostalgia and dial in to the newer offerings. Last night, the '90s spell was broken—as the Pumpkins proved on a blustery Tuesday night in Portland, you can never go back.