“Portland attracts creative people,” said Katie Behrens, a die-hard John Brophy fan — a self-described Ketten — on another night. “And when creative people do karaoke, they look for ways to make it better.” We were all drinking a beer on my last night in town, warming up for a night of Baby Ketten at a pizza place on Mississippi Avenue. Behrens is 27 and an aspiring comedian. That night she was between jobs. She was exuberant about her relationship with all the Kettens and with John in particular — “My record is 10 nights in a row” — describing him again and again as not just a K.J. but also a supportive friend who makes her a better singer, a braver performer, a better person. “My second family is Baby Ketten,” she said. “I’m part of something special. And I don’t have to sit by myself.”

At the pizza place, John and a friend were setting up his custom light stands and speakers. I tossed a couple of bucks in his tip jar and signed up for “Electioneering,” the Radiohead song I watched him make at his house, then bought a round for our table. “Let’s call Justin to the stage,” John announced, “for something I’ve never done before.” We heard the unmistakable bass line to the White Stripes’ “Seven Nation Army,” but the song was playing noticeably slowly — perhaps two-thirds as fast as usual. We looked at Brophy, who shrugged. A tall young man in a puffy jacket swayed up onto the stage, then kicked into the lyrics — but instead of imitating Jack White’s rock ’n’ roll keen, he sang in a rhythm-and-blues croon. The song was instantly transformed from dirty garage rock to bedroom soul. It sounded incredible, as if the song were written that way in the first place. When it was over, Justin bowed, accepting our applause, then replaced the microphone in its stand and walked out the door, never to return.

After that, my performance of “Electioneering” was somewhat beside the point, but thanks to watching Brophy build the track, I certainly knew the song cold. It’s amazing what a difference a great sound mix makes — Brophy mixes singers from his board on the fly, and there was no mud or muddle in the sound, just pealing guitars and me, doing my damnedest to put on a show. As soon as I was done, I put my name back on the list for the song I’ve been waiting more than 20 years to sing, a song I love, a song that scared the hell out of me. My favorite ballad by my favorite band; a song I assumed would never, ever be available at karaoke, because it’s a feedback-drenched, near-indecipherable dirge: R.E.M.’s “Country Feedback.”

But it would be a while before the rotation got back to me. Brophy’s policy, designed to make sure as many people as possible get a chance to sing, is that new arrivals are moved to the front of the line, so for the next two hours I sat at our table and watched the weird and wonderful karaoke scene in action. The comics critic Douglas Wolk sang Trey Songz’s “Bottoms Up,” tearing ferociously into the Nicki Minaj verse. Katie Behrens sang Dia Frampton’s “The Voice” version of Kanye West’s “Heartless” but lost her voice on the bridge. (Everyone cheered for her anyway.) A short woman in a wool cap and wire-rimmed glasses rapped Ice Cube’s “You Can Do It” with one of the tightest flows I’d ever heard. “That’s my sister,” said the woman sitting next to me.

“My neighbors are junk dealers,” she continued. “Not junk like heroin, junk like junk. They sell junk out of their yard. It’s the most Portland thing.” Addie Beseda had the short haircut that seems more common on women in Portland than anywhere else I’ve been, and seemed remarkably lucid for someone who, self-reportedly, had been celebrating the first day of a new programming job since she left work.

“Here’s the important thing to remember about Portland,” she said. “No one’s here to get rich. Unlike everywhere else in America. There’s a critical mass here of people here following their passions. Oh, it’s my turn, hold on.” She polished off her beer, jogged up to the stage and began what was, by a wide measure, the most amazing song I heard in my Portland karaoke odyssey: “Prisencolinensinainciusol,” a 1972 epic written in gibberish by the Italian performer Adriano Celentano, supposedly to mimic how English sounds to the Italian ear. It is like four minutes of “Jabberwocky” with a Continental accent and a mod beat. The karaoke version is a Baby Ketten original, of course. Addie nailed every syllable, then high-fived her fellow Kettens all the way back to our table. “So, yeah,” she said. “People from Portland do stuff like that.”

Portland isn’t just the capital of karaoke, I was realizing. The Japanese influence, the small-business climate and the abundance of bands don’t really matter. Portland is the capital of America’s small ponds. It’s a city devoted to chasing that feeling — the feeling of doing something you love, just for a moment, and being recognized for it, no matter how obscure or unnecessary or ludicrous it might seem to the straight world. It is the capital of taking frivolity seriously, of being silly as if it’s your job.