To folks who aren’t fluent in American Idol, there was probably zero appeal in the idea of Ryan Seacrest’s “Rock My Town” contest that brought season 8 stars Allison Iraheta, Adam Lambert, and Kris Allen to the Highline Ballroom in New York City last night. Too bad for them. Because all three singers delivered such powerful, confident sets from their recent debut discs that blind devotion to Fox’s ratings behemoth was hardly a requirement for getting left weak-kneed, sore-throated, and ultimately elated by the time the trio combined forces to close the show with Gnarls Barkley’s “Crazy.”

That said, seeing all three performers in an intimate venue like the Highline, as opposed to on a TV set or in the larger stadium setting of the Idols Live tour last summer, made it clear how each one connects to the audience from a different place: Allison, a teenager who at times seems blissfully clueless of the power her voice possesses, runs on pure instinct. Adam, acutely aware of the imposing force of his pipes (and, yes, his body), is happier in the role of a ringmaster guiding his rabid fans to the brink of collapse. (One woman had to be carried out in what Idoloonies affectionately term a “Glambulance”). And while Kris, the scrappy season 8 champ in the unenviable position of playing for an audience a third smaller than the performer before him, could have followed a crash-bang fireworks display with an intimate slide show (without anyone holding it against him), he did something perhaps not even his biggest fans would’ve expected: Casting aside the manacles of expectations and comparisons, he lost himself in the age-old art of rocking out with his very excellent band…just like a closing act is supposed to do. But onto specifics.

On the ballads “Just Like You,” “Trouble Is,” and “Scars,” Allison managed to plumb the depths of love’s dark side — bitterness, addiction, vulnerability — with a ferocity that ought to be impossible for a teenager who goofily explained to the audience that her keyboardist/musical director writes the command “don’t suck” at the top of her set list every night. (As IF!) In the night’s funniest and most instructive moment, Allison got halfway through the first verse of “Scars” before stopping her band and admitting she’d started in the wrong key, then proceeded to leave everyone breathless with a take-two vocal that chart-toppers like Taylor Swift or Miley Cyrus wouldn’t be able to touch with 10 feet of Auto-Tune. And please check for a functioning pulse if you were in the audience and failed to flail during raucous stomper “Holiday,” the “down with technology” anthem “Robot Love,” and a positively epic take on Roberta Flack’s “Killing Me Softly.” When Allison (rocking killer pig-tails and a black-and-white minidress that woulda fit in nicely in a John Hughes ’80s flick) is connecting with her music — as she did in every single song of her “Rock My Town” set — you sometimes find yourself shaking your head in disbelief: “How is a kid capable of all this?” I can pretty much sum up her set in two words: “I mean…”

The crowd seemed to suddenly double in size the moment Adam took the stage for a set that can only be described as insane on every level. There were moments when you’d have believed the season 8 runner-up was 11 feet tall, the way he stalked and preened through uptempo numbers like “Sure-Fire Winners,” “Strut,” and “If I Had You,” and that’s not even acknowledging the gyrations! Adam doles out the hip-thrusts, the neck-twists, and the open-palm-to-the-pelvis shenanigans with an almost Tantric quality: His raw sexuality is so much a part of his show, it should get billing as an additional member of his band. But the over-the-topness of Adam’s act wouldn’t work if he didn’t have the vocals to match. On “Sleepwalker,” “Soaked,” and current single “Whataya Want From Me,” it felt like the force of his instrument could’ve filled a football stadium (sans microphone). Part of the reason Adam inspires such rabid fandom, I think, is that he’s so aggressively outre that he erases any feelings of ridiculousness his ordinary fans might feel when singing in the shower or dancing in front of the bedroom mirror or just generally dreaming of breaking out of the humdrum of everyday life. He’s at once fantasy and wish fulfillment. Dis him, dismiss him, ban him from ABC — the dude is having way too much fun to concern himself with such trivial slights. He’s a modern-day Pan for our TMZ times. Oh, and if his label has any shred of common sense, it’ll eventually serve the Lady Gaga-penned “Fever” to radio. Adam’s live rendition is a romping crowd-pleaser in a way that screams “song of summer 2010.” Seriously!

Adam is, undoubtedly, a tough act to follow, and when a wave of Glamberts left the building before the start of Kris’ set, you could feel some of the energy drain from the room. If that bothered the season 8 champ, however, it wasn’t evident in a performance that teemed with creativity, bravado, and moments of pure audacity. I mean, seriously, as groan-inducing as an acoustic “Heartless”/”Gangster’s Paradise” mashup sounds on paper, it’s downright magical delivered by the Pocket Idol and his harmonizing band of brothers. Ditto for the “Falling Slowly”/”With Or Without You” jam session that worked not only musically, but also thematically, capturing the excitement/angst of diving into, then maintaining, a romantic relationship. Better still, though, in a set that also found Kris covering the Beatles (a much more rockin’ arrangement of “Come Together” than he managed on Idol) and Michael Jackson, it was his original material that played best of all, particularly the bluesy breakup anthem “Is It Over,” the achingly bittersweet “The Truth,” and jaunty lead single “Live Like We’re Dying.” By the time Kris led a sextet of fans up on stage to help him deliver the “yeah-yeah yeah-yeah” chants of “Alright With Me,” the crowd in the palm of his hand, you could still see the humble season 8 everydude with the workmanlike charm, but also something more — a commanding solo artist ready to compete with the Mrazes and (ick) Mayers of the world.

Any of you catch the Kradison goodness in NYC last night? How about “Crazy” and that adorable group hug? Anybody wish deep down that these three cats would tour together for ever and ever and ever? Yeah, I know, my Idol fandom is showing, so let me just say two things: Follow EW’s Music Mix blog on Twitter @EWMusicMix, and do the same with yours truly @EWMichaelSlezak!