I wasn’t sure how I felt about fun. before their mainstage Sunday show at the Key Arena. I knew their rotation-heavy and end-of-school-montage-ready massive hit “We Are Young.” I knew one of them dates Lena Dunham. And I knew lead singer Nate Ruess’ vocal range had to be either perfect or completely auto-tuned.

I knew all I knew when the lights cut to black. Then an ominous recording of swelling voices, heavy drumbeats, and powerchords. The crowd lost it. Ruess et al appeared on screen, in all black tuxedos. Or maybe suits…I was in the nose-bleeds in the packed Arena. But wherever you were it was all so dramatic, tuxedos/suits and piano and harmonies. Cut to black again.

When the lights came up, it was over. For the next hour the drums beat hard and steady, and the fist pumps from the crowd and the stage alike were aplenty. fun. has one mode and that’s anthem. And they have one goal, and that’s to make you FEEL IT ALL. And Mr. Ruess was everything you’d want in a frontman. His white sneakers glowed as he ran, jumped, skipped and flew across the stage like he was about to set the world on fire because toni-ight-e-ight…we are young…wait, not yet. fun.’s most recognizable tunes will be heard, later. Mr. Ruess’ unfortunately Bieber-esque white suit jacket over purple oversized jersey aside, he worked hard to keep our attention, flirting with the crowd through sly grins on the megascreen and yelps about…well, I’m not sure because up in the nosebleeds all sound in KeyArena gets pretty tinny and words blend together. But I bet it was about something emotional but ultimately uplifting.

For me, the uninitiated in the world of fun., the first half hour blended together. It was first pump, Ruess’ signature shriek, crowd frenzy, pause, drop the beat and repeat. A good formula, but fun. wants, nay needs, you to feel more.

So cue the call and repeat about feeling alive. Cue the backlights and screen as bright and neon as every 16 year-old’s outfit at this year’s festival. Cue the confetti bomb. fun. has us in their grasp now—and then they dropped their mega-hit “We Are Young.” I don’t know if it was the hope for more confetti bombs, or people actually were feeling all those feelings, but there was no mass exodus after their hit a la Gotye at Bumbershoot 2012.

When fun. left the stage an annoying 15 minutes before their set was scheduled to end to fabricate an encore in the tight-as-fun’s-harmonies festival schedule (okay, I was starting to understand the fuss), they came back with a one-song, no-holds-barred finale of “Some Nights.” The crowd’s “whoa-oh”ing filled the Arena. Even us up in the nosebleeds stood up and danced. Wait, us? Did fun. convert me with their infectious powerpop? Maybe just for that one night, baby, when we set the world/KeyArena on fire…because toni-ight-e-ight…