“God Help the Girl” has its Madison premiere on Sunday, Nov. 23 at 3:30 p.m. at the Union South Marquee Theatre, 1308 W. Dayton St. as part of the UW Mini Indie Film Festival. Not rated, 1:51, two and a half stars out of four.

“God Help The Girl” was written and directed by Stuart Murdoch of Belle & Sebastian, and the charmingly slight musical at times feels like one of those monochromatic Belle & Sebastian album covers come to life, with attractive young folks staring wistfully off into space.

But it’s hard to sustain a single tone for nearly two hours, and “God Help the Girl” only fitfully bursts to life, mostly when Murdoch’s songs possess the characters. Otherwise, there’s a lot of standing around, gazing, waiting for one of Murdoch’s next compositions (he started the project as a pop opera, then a concept album, before turning into into a film) to kick in.

Eve (Emily Browning of “Sucker Punch”) is a moody Glaswegian fond of slipping away from the mental health facility where she’s supposed to be resident. Wandering the streets of Glasgow with songs in her head, she happens into a couple of fellow believers in the power of a pop song. Cassie (Hannah Murray) is a powerhouse singer, while James (Olly Alexander) is a delicate guitarist (“I have the constitution of an abandoned rabbit”) who takes music, and Eve, very seriously.

Together, they start a band, of course. This is one of those musicals when any characters can break into song at any moment, and when they do, a wave of sweetness just washes across the screen. Instead of going for complicated widescreen choreography, Murdoch goes for handheld, up-close camerawork, and the desultory dance moves the actors do look like the sort that teenage girls in their bedroom listening to the radio might imitate their idols doing. A little clumsy, definitely charming.

The wisp of a plot involves a love triangle that develops between Eve, James and an arrogant punk singer in town. We know she should end up with James, but if she breaks her heart, it will give James the fuel for some more great songs, so who’s to say which ending is the happiest in Murdoch’s eyes?

Fans of Belle & Sebastian music will eat all this up with a plastic spoon, and even harder hearts may be won over by the spirited performances of “Musician Take Heed” or “Pretty Eve in the Tub.” I just wish Murdoch hadn’t been so smitten with his trio that he wasn’t ruthless enough to cut 20 minutes or so out of the film.