"The Broken Circle Breakdown" is undoubtedly one of the best films you'll see this or any year — passionate, joyous and heartbreakingly sad — but it's also remarkable for being one of those rare music films where a fictional on-screen band goes on to actual off-screen fame.

The film follows two Belgian aficionados of American bluegrass music in a story about "life, death and everything in between," as director Felix van Groeningen has described it, and for once, that's not just hype. The relationship between musician/back-to-the-land dropout Didier and tattoo-artist Elise is born of and poured into the music they make, and as such, it was vital for the cast to really perform it. Actor-writer Johan Heldenbergh plays banjo and sings in the film, while co-star Veerle Baetens also sings for real; backed by a tight ensemble of roots musicians, they're not just adequate but outstanding.

The soundtrack, which features great renditions of such classics as "Wayfaring Stranger" and "If I Needed You," was a huge hit, topping the charts in several European markets and even reaching No. 19 in the U.S. This prompted the band to hit the road with the film's stars front and center, and their latest Broken Circle Breakdown Bluegrass Band tour is looking at 32 sold out shows between March and June.