Make a C with your left hand, make a backward C with your right; put them together and point thumbs south.

If Never Say Never is an accurate thermometer, then Bieber Fever - the pubescent-female passion for popster Justin Bieber - is North America's happiest epidemic.

From Bieber's modest beginnings in Stratford, Ontario, almost 17 years ago to his Madison Square Garden concert last August that sold out in 22 minutes, Never Say Never is one part backstage biography, one part concert film charting the roots and meteoric rise of Justin II, successor to that supernova surnamed Timberlake.

Bypassing the Disney and Nickelodeon machines that reliably mold disposable teen sensations, Bieber got attention via YouTube videos of him singing Chris Brown tunes.

One of these DIY videos caught the eye of Atlanta-based entrepreneur Scooter Braun. Braun introduced him to R&B star Usher and to producer L.A. Reid, who shrewdly assesses Bieber as "the Macaulay Culkin of music." (Bieber shares with child stars Culkin and Leonardo DiCaprio those tousled blond locks and that rosebud mouth.)

What the 3-D film lacks in cinematic charm and ingenuity is compensated for by its subject's high-wattage charisma and low-key earnestness. This is not A Hard Day's Night, even if Bieber has a Beatles haircut and shakes windswept locks like puppy emerging from tub.

Replete with home movies of Baby Justin banging drums, kindergartner thwacking T-ball, and preteen strumming an oversize guitar, Jon Chu's film bounces to the Tiger Beat. Bieber fans describe their crush object in words like adorable.

Chu, who directed Step Up 3, has fun with the 3-D effects here, most of which involve JB pointing his finger at the audience, creating the illusion that he is pointing directly at you. (Cue high-pitched shrieks.)

In scene after scene, we see that the hardest-working 16-year-old in show business is still an ordinary kid who likes pizza and shooting hoops and still has to hit the books (he's tutored on the road). Bieber is buoyed by what his voice coach "Mama Jan" calls a "functional dysfunctional family," costumers and cheerleaders and dance coaches who help him make good choices, e.g., canceling a performance when his vocal cords are inflamed.

But the movie also acknowledges the 100-hour workweeks of this overnight sensation who made appearances at high schools and radio stations across the country to build his fan base and endear himself to disc jockeys. On stage variously with Boyz II Men, Jaden Smith, Miley Cyrus, and Ludacris, Bieber carries himself like a squeaky-clean homeboy with an angelic voice. On him, swagger looks sweet.

Still, Braun and Bieber's mother, Pattie Mallette, worry about the teenager's intense professionalism. Braun recalls the Video Music Awards in 2009 at which Madonna eulogized Michael Jackson saying, "He never had a childhood."

"Don't let that happen to me," Bieber said to his father surrogate. Amen.

Justin Bieber: Never Say Never *** (out of four stars)

Directed by Jon Chu. Distributed by Paramount Pictures.

Running time: 1 hour, 45 mins.

Parent's guide: G (nothing unsuitable for children)

Showing at: area theaters


Contact movie critic Carrie Rickey at 215-854-5402 or crickey@phillynews.com. Read her blog, "Flickgrrl," at http://www.philly.com/philly/blogs/flickgrrl/