Back in 2006, musicians Glen Hansard and Marketa Irglova starred in a film that shocked both the box office and the Academy Awards. Made for $100,000, the John Carney directed musical romance Once became the little movie that could, sticking around for months in theatres and netting an Oscar for the two singer-songwriters for the song “Falling Slowly.” The duo, known formally as The Swell Season – which also serves as the title of a new documentary about their life on the road and their personal interaction – became a bit of an international sensation that has been selling out shows and playing festival gigs around the world ever since.

It’s a great story, but despite having three directors on the documentary project designed to give fans of both the film and the band a glimpse behind the curtain, the appeal is limited and the scope of everything is distressingly narrow. While watching Once is a prerequisite before going into this film and having a love for the band’s non-film related material will help, the audience for this film really begins and ends with Swell Season fans and the mildly curious.

Between lengthy montages that belie a lack of focus (possibly brought on by too many cooks in the directing department) and some sometimes superfluous asides designed to pad out a 90 minute running time, viewers can easily see why Hansard and Irglova were such magnetic personalities in the first place. In the many performance segments of the film, Hansard’s intensity on stage and Irglova’s down to Earth shyness come through beautifully and do more to illustrate their relationship and seemingly preternatural songwriting chemistry than the film’s countless segments depicting autograph signings and post concert drinking sessions.

This isn’t to say that there isn’t a great deal of personal insight, but it’s quite likely that these aren’t the insights that fans are necessarily looking for or that the unfamiliar will be looking for. Much of the film’s personal story surrounds Hansard’s upbringing with his alcoholic father and doting mother in Ireland. The filmmakers go a long way to show how a man who dropped out of school to pursue his rock star dreams taps his own life for inspiration, but on the flip side, Irglova’s downright aversion to being on camera makes her seem a bit more histrionic than she probably is in real life. Uncomfortable with success, fans, and her true devotion to the touring lifestyle, there is precious little known about her past to suggest that she isn’t just coming across as burnt out or unreasonable.

Those looking for some insight into the duo’s former romantic relationship will also be sadly out of luck until the last 10 minutes of the film, and even then it’s all maddeningly dismissive because this is a movie that’s all about the music, man. That music is good and almost enough to warrant a pass for the film, but it’s hard not to shake the feeling that this is all more designed to be a bonus DVD to be packaged with a live album at some point rather than as a serious cinematic effort. Aside from some well shot black and white cinematography, nothing here is particularly cinematic in the way their original big screen outing was. Swell Season is a film that preaches to the already converted and least picky fans of the band, but it might not even be able to properly capture just what the audience gets from their live shows or the music that drove their first big success.