In the decade-plus since the Wonder Years formed outside Philadelphia, there have certainly been more popular and beloved pop-punk bands, but very few have insinuated themselves so credibly into the conversation as a band to believe in. The Wonder Years put themselves forward as the type of band a young fan could build an identity around without worrying that it would seem embarrassing years later. That’s proven remarkably true: Even as predecessors like Brand New have slid into ignominy, the Wonder Years—tracking a roughly parallel creative arc—have kept going, leaving suburban frivolity behind for broader musical horizons, darker thematic material, and dozens of imitators.

As much as the Wonder Years’ five previous albums followed the broad tenets of modern pop-punk—nostalgia for a youth they’re too young to realize isn’t even over yet, the melancholy of the middle-distance tour schedule—a specificity of place has distinguished their music from all the soundalikes. Frontman Dan Campbell is a Philly Springsteen in an extra-medium hoodie, filling his lyrics with diners, basements, bowling alleys, and parks that delight local kids and make the songs come alive for people who’ve never set foot in his city. But every successful band eventually outgrows its hometown, and it’s clear on the Wonder Years’ sixth album, Sister Cities, that they’re struggling with where they fit in as citizens of the world.

“It’s a record about distance, or maybe how little the distance matters anymore,” Campbell recently said, hinting at the feeling of international saudade that comes through in nearly every song on Sister Cities. Even its title comes from an idealistic international program that Dwight Eisenhower launched in 1956 (and a park in Philadelphia that was the result of that effort). This is an album about how art lets us attempt, and sometimes fail, to relate to the rest of the world. The band underscored this theme with a pre-release scavenger hunt involving unlabeled vinyl records with spoken-word poems in various languages. “I left pins on a map. I’m handing you the string,” the band tweeted. “Tie them together. Unite us...” To those not already enthralled by these guys, it might have come off as some Radiohead-ass nonsense. But with the Wonder Years, it’s hard not to be swept up. As in everything else they do, there’s an overpowering sense of earnestness and vulnerability that makes it work.

They wrote the title track on Sister Cities, a characteristic toggle between quieter bass-led verses and cathartic, shouted choruses, when they were adrift in South America a few years ago. Campbell and company, lost after a canceled performance, found themselves at Santiago, Chile’s version of a sister city commemorative monument. Eventually a group of locals helped them put together an impromptu show. “I’m laying low/A stray dog in the street/You took me home/We’re sister cities,” Campbell sings. Even when he’s singing about finding community, there’s a sense of being on the outside observing.

That sense of insecurity and displacement comes to define the album, making it a more subdued record than the Wonder Years’ previous onslaughts of heroic underdog anthems. Album opener “Raining in Kyoto” revolves around another act of unprompted kindness from strangers, as Campbell attempts to honor his dying grandfather at a shrine “an ocean away,” and a Japanese man ushers him through the proper steps. But the guilt and pain of distance still shadow his thoughts: “You’re half-awake/And I bought you a radio to play the blues away/With my hand to hold, you asked about the way you wish they’d let you die at home.”

On “It Must Get Lonely,” a weary, slow-build track that forestalls the inevitable furious outro chorus for minutes of resigned meandering, Campbell confronts Irish seas, English streets, and “Montmartre in Paris where the crows seem to know my name.” That musical restraint, also heard on this album’s “We Look Like Lightning,” “Flowers Where Your Face Should Be,” and “When The Blue Finally Came” (the latter two of which withhold any payoff whatsoever), isn’t a new technique for the band, but its prevalence here is indicative of a progression in their technique. There are choruses, but they’re fewer and further between than on any previous Wonder Years album.

It borders on critical malpractice to call the Wonder Years a pop-punk band at this point—not because that term is a pejorative, by any means, but because it implies a creative stagnation that couldn’t be farther from the truth. Fans of big, stadium-swinging hooks might find Sister Cities a sparser, more introspective affair than they prefer, but the band seems okay with leaving South Philly basements behind and seeing more of the world. After doing so much to put the spirit of their hometown into music, they’re aiming for something larger now.