Each week, Lizzy Goodman guides you through the dirty streets of rock and roll.

The weirdest thing happened this week. I saw Wilco play twice -- once in David Letterman’s relatively sterile TV studio  and once surrounded by the lush greenery of Central Park at one of the last Summerstage shows of the season. I left Summerstage irritated with one of my favorite bands for turning into purveyors of meandering stroller rock but I left Letterman feeling like they had restored my faith in rock and roll. How did that happen?

It wasn’t about different set lists, as both nights the band played relatively similar selection of old and new tunes. It wasn’t the crowd, as the Summerstage audience -- microbrew-sipping Gen X-ers with kids in tow, who did cute things like spin around and dance on bleachers -- was vastly more ostensible fun than at Letterman with a slew of industry insiders and screaming superfans. All I know is that from the second I showed up, soaked (I maintain that umbrellas are a prissy affectation) in the early evening for the "Live at Letterman" Wilco performance, things were just instantly awesome.

The series is held seemingly according to no real schedule or plan. Sometimes emails appear in your inbox announcing that a band who performed on Letterman that afternoon will also play a special gig in the studio later that evening. So there is a kind of serendipitous feel to the whole thing. That sense of unexpected awesomeness on the horizon continues inside, where you wait in line to get into the studio and everyone runs into friends they didn’t know would be there. By the time the doors opened at the Wilco gig, the scene in the lobby was like a bunch of giddy kids before a field trip, or on their way to summer camp where we might all play in treehouses and form crushes on each other and sneak out of cabins to misbehave.

The band opened with two new songs: “Art of Almost” and “I Might” off the recently released and surprisingly rocking The Whole Love. “Did you get in here for free?” said Jeff Tweedy, who is adorably bowlegged in person, with his signature shy wit. “Good, then there’s nothing to complain about. You will enjoy every second of this.”

Yes sir! And perhaps as a gesture of good will, the band then launched into the erratically melodic chimes of “I Am Trying To Break Your Heart,” off their celebrated opus of indie rebellion, Yankee Hotel Foxtrot. I think that might have been when the show became cool not only because you’re in a small space with one of the tightest, loudest, most self-confidently odd bands in rock history but also because in that intimate setting a song like “Heart” feels suddenly fragile and delicate and even more like a thing you are lucky to be alive to witness.

By the end of the set, Tweedy was standing with both feet on his guitar pedals and drummer Glenn Kotche was flinging visible beads of sweat in a kind of halo around his kit and superhuman guitarist Nels Cline was doubled over wailing like a possessed teenager. I forgave Wilco for every album of elevator indie rock they have already made and for all the ones they will make in the future. These guys still convey that signature and increasingly rare sense of exhilaration and danger that we all came here for in the first place. “We don’t have much time left,” Tweedy said with a mischievous grin. “But we will play until they make us stop.” You’d better.