Mariah Carey and her entourage move through the MTV hallways in a flying wedge, backing Taylor Swift into her dressing room. That room's approximately the size of a shoe closet, but Swift doesn't care. Today is going to be her first time performing on TRL — but it's her second time visiting the MTV show's Times Square studio. Back when Swift was sixteen, she snuck into the studio to see Hillary Duff. A lot's happened in Swift's life since then. She's had 40 million visitors to her MySpace page, her album's been on top of the country charts for fifteen consecutive weeks and three of her hit singles have crossed over to the pop charts. And she's reached the ripe old age of eighteen.

Before the show, Swift records a bunch of PSAs. The sound guy is pleased to discover he can clip a wireless microphone to one of her cowboy boots. "It's never okay to ignore discrimination," Swift intones solemnly into the camera. Then she has a question for the director: "You want me to say it three different ways so you guys have options?"

"Sure," he says, slightly flustered. "Maybe you should be directing this."

Swift performs "Teardrops on My Guitar" sporting a black dress and a sparkly silver guitar that matches her eyeshadow. The song's about being friends with a boy who's crushed out on another girl. "There he goes, so perfectly / The kind of flawless I wish I could be," Swift sings, sounding totally lovelorn — but with wavy blonde hair and long legs, looking ridiculously flawless herself. During the guitar solo, Swift leans back, sees herself rendered several stories tall on a Times Square video screen, and nods at her guitarist.

"I will remember that moment for the rest of my life," Swift says later that day, on a private plane heading down to Greenville, South Carolina. "It was a little nod of 'this moment rocks.'" Swift and her crew are crammed into the eight-seater Learjet like gerbils in a thermos. Her sound guy is sitting on the plane's toilet.

Taylor scrolls through some pictures on her iPhone: the most recent set are from her eighteenth birthday party last December, when her record label gave her a pink pickup truck. (She donated it to charity.) In an early photo session, Swift drew a heart on her left foot with a magic marker, and then vowed that if her album sold two million copies, she'd get that heart tattooed. Now that she's sold more than 2.5 million copies of Taylor Swift, she has a karmic date with a tattoo needle, but she's looking for a loophole. "I can back out of it," she insists. "Mostly because my dad said he'd take it off with a belt sander."