Like Disney-created tween idols (Hilary Duff, Miley Cyrus) and TV-boosted boy bands (the Jonas Brothers, O-Town), Lady Gaga apparently comes with an expiration date.

In 2010, she was the biggest pop culture figure of this century. All over the radio, magazines, the Internet, dance clubs, TV, Twitter. The queen of all media. She filled St. Paul's Xcel Energy Center for two consecutive oh-my-Gaga nights.

Now, Gaga isn't on the radio. Or the pop charts. Or the Grammys. On Wednesday, she had trouble filling the Xcel (there were plenty of last-minute giveaways to bring the crowd to a near-capacity 14,000). And frankly, there wasn't the same buzz in the building as last time. What could we expect when she's on tour to promote an album ("Born This Way") that was released in May 2011?

Not only is Gaga missing from the media, but she seemed almost invisible at the Xcel. Let me repeat that: The most garish, gaudiest pop supernova of this century was almost invisible during her second arena tour. Hard to believe.

She wore all kinds of masks -- from an elaborate headdress that appeared like a catcher's mask for a stage character in "The Lion King" to a white leather get-up that suggested deer antlers. Between numbers, she usually disappeared, with no action on the stage from either her 12 dancers or her five musicians. Too often she didn't assert her voice during songs, letting the recorded backup singers carry the choruses while she concentrated on choreography in some ridiculously awesome high-heeled footwear.

Not that Gaga was bashful. She talked plenty, about herself and self-love. But it felt more self-aggrandizing than self-empowering. Even when she tried to explain the concept of her set-in-a-medieval-castle show -- something about government-owned alien territory -- it was incomprehensible. At least for her previous Monster Ball tour, she had a vague storyline with a "Wizard of Oz" meets "Rocky Horror Picture Show" vibe. The current Born This Way Ball tour is complex and disjointed, punctuated with Gaga-ish provocative weirdness -- from her entrance on a mechanical unicorn to her raw-meat dress, raw-meat couch and dumping Mother Monster herself into a giant meat grinder. You had to be there.

Indeed. Because when she got out of her Gaganess, the 26-year-old New Yorker proved to be a warm, compassionate and loving human being. She got all choked up thinking about her grandfather and then performed a tear-filled "Edge of Glory" solo on the piano. Her voice was rich, impassioned and gorgeous in a pop-star kind of way. Then she picked up her cellphone and called a fan, Chelsea, in the crowd and sang another piano number, "Born This Way," to Chelsea -- and all her fans. For two marvelous moments, the specialness and the genuineness of Lady Weirdo sparkled.

For the encore of "Marry the Night," she handpicked seven fans from the audience to join her onstage. Even though the rendition of the big dance hit turned out to be all introduction without the big disco climax, this presentation made it clear why Gaga, even though she's no longer hot, still matters to her Little Monsters: Those seven fans followed her around like she was the Pied Piper of the misfits and the misunderstood. Twitter: @jonbream • 612-673-1719