The K-pop world has developed its own lingo: “hi-touch,” a way for artists and fans to connect quickly, a sort of extended high-five; “bias,” the member of a K-pop group that you favor; and so on. Much of KCON is devoted to efforts at fan education and inclusion, especially during the daytime part of the festival — a dance floor was set up so fans could recreate the moves from their favorite K-pop videos en masse, and at the myriad sponsor tents, teenage fans sang and danced along to hits like BTS’s “Blood Sweat & Tears.” Merchandise booths offered cheap ways to show loyalty: posters, stickers, enamel pins, bracelets with stars’ names spelled out in glittery letters.

Most of the extremely diverse fans here were teenagers, not that much younger than the performers onstage. K-pop skews young as a genre — one reason is that South Korea mandates military service for its men, a law that extends even to pop idols. Many in the most recent wave of the genre’s superstars, like the members of BigBang, have recently entered the military, or are about to. Groups like BTS are beginning to fill that void and, if its reception here is any indication, NCT 127 is hot on its heels.

All of which made the headlining performance of CNBLUE all the more curious. Though the group is all-male, it isn’t a classic boy band; rather it’s a pop-rock band, and all the members, including the charismatic frontman Jung Yong Hwa, played instruments. Of Saturday night’s performers, it was the most established, having been releasing music since 2009. Its music, which had glimmers of Abba and also Phoenix, had little to do with what was happening during the rest of the show.

Its set was colorful, but also loudly served as a reminder of how young everyone else was, and by extension why K-pop hasn’t been able to gain steady, reliable traction in this country. Just as artists are reaching the peak of their renown, they are snatched away, leaving behind seeds that are only just beginning take root.