A funny thing happened to emo in the 1990s: The "emotional hardcore" (or emo-core, and then just emo) that originated with Rites of Spring and their Revolution Summer peers diverted into plain, old-fashioned pop. Cap'n Jazz's wildly unpredictable, barely adolescent outbursts gave way to the Promise Ring's milder and eventually moribund pop rock (ignore the ongoing weirdness of Joan of Arc here for a second). Braid's dizzy circling lyrics and guitars slowed down enough to allow for Billy Joel and Burt Bacharach covers (and eventually for the formation of the utterly forgettable Hey Mercedes). Jawbreaker, if they were ever properly emo at all, embraced bigger, radio-friendlier (though still great) pop punk, and they posthumously begat the more classically rocking Jets to Brazil. Local heroes Sunny Day Real Estate broke up after recording two classic albums, got back together, and went weirdly prog (or, in the case of Jeremy Enigk's intervening solo work, orchestral). It's been all downhill from there—or, as Get Up Kids guitarist Jim Suptic told Rolling Stone earlier this year: "The punk scene we came out of and the punk scene now are completely different. It's like glam rock now... If this is the world we helped create, then I apologize."
The Get Up Kids may have some things to feel sorry about, but for a moment there, in the growing pains between their early emo and their late-period pop rock, they and their aforementioned peers made some great records.
The Get Up Kids' debut full-length, 1997's Four Minute Mile, was typical but expertly executed second-wave stuff, balancing big sing-along choruses and unexpected hooks with unconventional song structures and changes, hard and fast breaks of drums and guitars, and raw-screaming feelings. Those feelings are of the teenage variety (the band recorded the album over one weekend while still in high school): Love is either invincible and magic or all-consuming and crushing, fraternal friendship is an inviolable brotherhood, loyalty and honesty are paramount virtues, the waiting (and the missing) is the hardest part. You can hear the seeds of the coming genre caricature here—the keyboard-buoyed chorus of "Don't Hate Me," the redlining melodrama of "No Love"—but the balancing act works.
Their 1999 follow-up EP, Red Letter Day, took these tendencies further. Coalesce drummer (and evil genius behind Reggie and the Full Effect) James Dewees joined the band on keys full-time, adding sentimental piano tinkling and cheap-seats synth lines to the band's songs. Matt Pryor's songwriting increasingly forwent their debut's Outsiders-y teen angst (about fitting in and friendship and finding yourself) in favor of more traditional songs about girls (though with the geographical references typical of mid-'90s emo).
By the very first sound of that year's excellent sophomore album, Something to Write Home About—the big, dual electric-guitar slide and stomping, stadium-sized kick drum introducing "Holiday"—the transition to pop was complete. The album even had a just-syrupy-enough ballad called "Valentine" with a chorus that goes "Will you be my valentine?" (To be fair, it also has a sweet and soundly landed "Jinx Removing" reference on album closer "I'll Catch You.") The band released two more studio albums before they broke up in 2005, but there's not really much worth fucking with after Something to Write Home About besides a few covers and rarities collected on 2001's Eudora.
The Get Up Kids' career arc is just one of many, but it's pretty typical of what was happening to emo acts at the time. And there was something subtly conservative, both musically and ideologically, about this shift toward pop. Where emo-core was a liberalizing, progressive development from within the increasingly rigid world of hardcore—questioning the deification of male aggression, looking beyond the militant Spartanism of straight-edge, opening up the floor to deeper emotional discussions, maybe even allowing for the direct involvement of the ladies at some point—this pop turn felt like a regression toward more conventional songwriting tropes, matched by the Get Up Kids' lyrical content with its idealization of male camaraderie and emphasis on monogamous romantic loyalty/fidelity across time and distance (the girl is always at home waiting, the guy is always drawn out to the road).
Still, those few Get Up Kids albums are stone-cold classics, and reports from the band's reunion shows thus far indicate that they're pretty much playing Something to Write Home About—now enjoying its 10th anniversary—in its entirety. So forget about the late-career flubs, forgive them their guylinered descendants, and for one night emote like it's still 1999. 
