The side-by-side release of U2 3D and Hannah Montana & Miley Cyrus: Best of Both Worlds Concert invites you to line up the pop past and pop future in fascinating tandem. It's routine wisdom to say that U2 is the greatest rock & roll band of the past 25 years (depending on the day, I'd go with R.E.M., but who's quibbling?), yet this raises a question: Will the next 25 years produce a band with the passion and power, the transporting sweep, of U2? The rise of the tween-fashionista mechano-pop juggernaut Hannah Montana doesn't bode well.

I can't, offhand, think of an entertainer who could dignify the prospect of a 3-D movie more than Bono. If he says 3-D is a noble cause, that's good enough for me. I wasn't sure what to expect from U2 3D — the Edge tossing guitar picks into our faces? — but the film, shot in South America during the band's Vertigo tour, comes at us in images that are nearly sculptural. The 3-D visuals envelop you, majestically, and that effect fuses with the band's surround-sound rapture to create a full-scale sensory high. U2 3D makes you feel stoned on movies.

On this tour, U2 had cleaned away a lot of their stage bric-a-brac, and what we're left with is great songs (''Pride,'' ''One,'' the incomparable ''With or Without You''), plus a few duds (''Bullet the Blue Sky''), as Bono, with his soaring message of global love, rules the crowd like a hippie cult leader. The Edge doesn't just create walls of sound — he creates cathedrals of sound. It's hard to imagine, in the digital era, downloading a band as monumental as this one.

Rock & roll may never die, but you know it's been eaten by the consumer culture when you see Hannah Montana & Miley Cyrus: Best of Both Worlds Concert, in which the bouncy diva of prepubescent bubblegum pantomimes every rebel-yell gesture in history, all to exalt girl-power attitude as something you can acquire. Hannah is presented, explicitly, as Miley Cyrus' alter ego (she performs first as Hannah, then as herself — the only difference being Hannah's blond wig), and that's a stroke of marketing genius, since what it says is that anyone can be Hannah. Cyrus, an apple-cheeked dumpling, resembles Pia Zadora, but when she exhorts the crowd, it's with the martial efficiency of Hillary Clinton. Her music isn't even trying for the beauty of, say, Backstreet Boys, but her message is commanding: It's that girl power has trumped boy power. The sound leans on Avril Lavigne's prefab buzz guitar, but it also draws hooks from '80s songs like ''Kids in America'' and ''Summer of '69.'' As a soundtrack for empowerment, not to mention tween shopping (is there a difference now?), one could do worse.