Walking up Sanchez Street on our way to the Noe Valley Ministry, we passed by Glen Hansard and Marketa Irglová (a.k.a. The Swell Season) strolling smilingly toward 24th Street, not a care in the world. They didn't look like two musicians preparing for a concert and they certainly didn't give off the air of being the stars of Once, a truly incredible film that's currently playing in theaters. They were enjoying each other and the calm, cool twilight - a sure sign that it was going to be a good night.

The Saturday before last we saw The Swell Season at Noe Valley Ministry, a small church that's home to the Noe Valley Music Series. We arrived just as the doors opened, in hopes of grabbing a seat near the stage, but were stopped in our tracks when our names weren't on the list. (Again. What's with our guest list luck these days?) Seeing as the ticket taker was a young woman sitting at a card table, and not a seasoned professional sealed behind a glass partition, we resolved to talk our way in this time. Ninety minutes, another street-side Glen and Marketa sighting (this time with his arm wrapped around her) and several conversations with Howard the tour manager later, we were escorted upstairs to a wooden bench at the side of the room, about 20 feet from the stage. The wait was worth it, because we had a clear view.

We'd missed the opener and were seated just minutes before Glen and Marketa came to the stage, which was sparsely set with a piano and acoustic guitar and flanked on both sides by an overflow of audience members sitting in the wings. Glen played the same acoustic guitar with the shredded body that he plays in the film and Marketa spent most of the set playing piano. From our angle to the stage, we could see her hands reflected in the piano's top, mirroring her movements to us like a chef's at cooking class.

It seemed that most of the audience had seen the film Once that stars Glen and Czech songstress Marketa as a struggling street busker and an inquisitive, aspiring singer, respectively. The set consisted mostly of songs from the film, several of which elicited enthusiastic whoops just in their first few notes. This wasn't just a performance by a great acoustic duo; there were so many layers to what was happening. Here were two musicians, friends and collaborators in real life, who'd made a movie - a movie in which their characters nurtured a great love for each other - and they were performing the soundtrack while stealing glances and beaming smiles at each other from across the stage. Perhaps we were projecting their film characters' emotions onto the real people, but trust us when we tell you there was a whole lot of love on that stage. A few times Glen called "Mar" (his nickname for her) over with a nod of his head to come share his microphone on a duet and the intimacy we witnessed almost made us feel like we were intruding on a private moment.

But this was a rare occasion when the audience and the performers were truly sharing a moment in time and an experience together. It's clear that those who have seen this film have been hugely touched by it, but it seems as though this fact was just dawning on Glen and Mar during this short tour through the U.S. Glen spoke candidly about his experience with the film's fans, describing how he and Marketa would be hanging out in Ireland as they always do, but that more and more strangers would approach them to talk about their appreciation of the movie. He noticed that the fans were pretty much all Americans, and when they set foot in New York City to start the tour a few weeks prior, they were overwhelmed by the positive response they got. As the frontman for the band The Frames, Glen described having spent the past 17 years always begging for a few more people to come to their next show, joking that by accumulating five new fans each time they came through a city, they could fill a decent-sized venue by the time he was in his 60's. After all that work, he described the response to the film feeling like doggedly tapping the world on the shoulder over and over for years and it finally turning around and saying "OK, what do you want?" He pantomimed a startled face with wide, blinking eyes as the punch line. Marketa had the best response to his recent shock; he recounted her telling him: "Well if you're going to flirt with popularity, don't be surprised when it turns around and offers you sex." She didn't say much in the live setting, but you can tell she has a lot to say behind the scenes.

With perfect acoustics and all the love in the room, the audience didn't want to see the show end, and Glen and Marketa didn't seem to mind drawing it out a little longer either. It was the end of their short tour and after spending some down time at the beach that afternoon, they'd enjoyed a walk around Noe Valley prior to the show. Was it always this cold and foggy this time of year, Glen asked? "Yes," the audience said in unison. "Wonderful!" he said with a sincere and wistful smile. They granted the audience two encores and Glen lead a singalong to "Banana Man", a hilarious song he wrote for his neice ("B-A-N-A-N-A-ah spells banana-ah!"). A little girl in the front row, asleep on her mother's lap, woke for the song and accepted Glen's invitation to dance on the stage during it. We've described shows as "intimate" before, but this was beyond anything we've experienced; it was like the wall between performer and audience dissolved and we were all just having a great time in someone's giant living room.

Once is an incredible film and you owe it to yourself to go see it. We're grateful to have gotten the chance to see Glen and Marketa at Noe Valley; it will go down as one of the most special shows we've ever seen. We have a hunch that next time we get to see them it will be in a much larger venue, and they'll have some Grammys and Oscars under their belts.

Photos by Steve Frauenfeld, who was sitting right near us and didn't mind us accosting him for permission to use his best shots. Please visit his Flickr page and Etsy shop.

Watch the trailer for Once: