Younger audiences, perhaps accustomed to the adopted personas of online realities, seem less bothered by questions of authenticity than previous generations. So it should be no surprise that the opening of " Jonas Brothers: The 3D Concert Experience," ostensibly a concert documentary, features a sequence of the band being chased by fans that seems "real" only in the same sense as an episode of " The Hills."

Directed by Bruce Hendricks, who also fashioned the recent Miley Cyrus 3-D concert movie, the film is awkwardly stitched together from candy-gloss arena concert footage and somewhat grimier-looking backstage/limo/hotel-room moments.

There is no attempt to make it all hang together as an organic whole, as the stop-start momentum of moving from onstage to off is mostly just handled by having an ornate Jonas Brothers logo swoop across the screen.

To heighten the film's three-dimensional effects, there is much flicking of guitar picks, spritzing of bottles, tossing of sunglasses and thrusting of microphones.

Be prepared to feel silly after you duck.

The band-on-the-run farce has been a staple of rock films since "A Hard Day's Night," and the freewheeling take on fandom of "JB3D" was done better in the underrated "Abba: The Movie." Here, far too often, the crowds are rendered as animal hordes of screaming mouths and grasping hands.

The Brothers come across more machine-tooled than homespun. The backstage footage doesn't even allow them the smart/cute/quiet/funny personalities of John, Paul, George and Ringo. They all kind of blend together. Their grasps for authenticity -- they do write their own songs and play their instruments -- just feel like another layer of artifice.

The songs bleed together too, one bouncing clap-along chorus to the next, mostly sounding like a modernized iteration of the glam-pop style of Cheap Trick or Redd Kross but minus the rust-belt roots or ironic self-regard. The one who mostly sings (Joe?) draws heavily from the Mick Jagger school of chicken dance arm flapping, while the other two bop around with guitars on, triangulating the stage so at no moment is a portion of the audience Jonas-less.

Shortly after a number with female pop songstress Demi Lovato, the equally young country singer Taylor Swift comes onstage. Flanked by her banjo dude and fiddle gal, Swift conveys a boldly assured stage presence and an emotional depth to her self-penned lyrics that make the tutored showmanship of the Jonases seem all the more hollow.

At a recent press preview screening, just listening to the audience full of teenage girls singing and clapping along to the Jonas recordings playing over loudspeakers before the film even started was a more emotionally vibrant experience than anything conveyed in the movie.

The audience's connection to these songs (and the Jonas Brothers) is genuine. The attitude displayed by "Jonas Brothers: The 3D Concert Experience" back toward those fans comes across as a curious mixture of shameless pandering and discreet contempt.

calendar@latimes.com