Every August, the world’s greatest pickers, strummers and fiddlers of “Old Time” and bluegrass music gather in Galax, Virginia, to compete, perform, jam through the night and drink corn liquor out of Mason jars.

It’s called the Old Fiddler’s Convention, and it is the Bayreuth of Bluegrass, one of the the longest running music festivals of its kind.

But for her gloriously tuneful documentary on it, filmmaker Julie Simone and Co. focused on young fiddlers, flat-pickers, mandolinists and virtuosos of the upright bass.

“Fiddlin'” is about tradition, a dying way of life, a small Southern town that’s lost the textile and furniture manufacturing the were its lifeblood for decades, but clung to its music. The film’s focus eventually settles on showing us a genre of string music that just like classical music, puts great stock in passing down its repertoire, musicianship and performance style, generation to generation, face to face.

Simone and her crew camped out at the 80th edition of the convention, back in 2015. And from the looks of the film, they began with no clear idea of who to focus on, just determined to get a lot of music on film, and musicians talking about it.

Touch on the history. Aim for inclusion, reaching out to old timers and youngsters, old men and boys, young women and girls, a lesbian flat-picker and a black ex-NFL player who has taken up the mandolin.

“Fiddlin'” gets at the difference between “old time” music, with its Scots-Irish and African roots, and the “fancy” offshoot popularized by Bill Monroe and generations that came after him — bluegrass. The schism between the two, good-natured as it is, hath not healed.

“If God had meant for people to play bluegrass,” one picker grins and growls, “he’d have put their fingernails on th’other side of their fingers!”

As with most documentaries, a story eventually makes itself clear and the movie sets to telling it in its latter acts.

Galax may have lost its industry, but the instrument makers who have long made it their base of operations have grown world famous, their guitars, violins, mandolins and banjoes coveted by everybody in Nashville, and found a global customer base, including Eric Clapton. A generation of luthiers like Wayne Henderson and Tom Barr have begun passing down what they know to their children.

Similarly, the generation of performers who learned the 200 year-old style of music from relatives and others they crossed pathso with are making it their business to ensure a new generation is there to take their place.

And the result, Simone’s team discovered, was several schoolbuses full of old time and bluegrass prodigies. Kids like Ivy Phillips and Presley Barker, Kitty Amaral and Eli Wildman have gotten hooked and taken to their instruments with the passion of fanatics. Through conventions like this one, personal encounters with legends and Youtube’s treasure trove of archived performances, the kids have mastered the music much younger than their forebears.

The performances here, gathered mostly at campsite jam sessions, under the various meet-and-pick tents all over Felts Park in Galax, or on the stages there, are just jaw dropping.

The convention lures some 1400 competitors to battle for blue ribbons in music and flat-footing, the Appalachian clogging dance style that old time music was invented to be danced to.

And some 40,000 spectators come to hear, sing, flat-foot and maybe even whip out their spoons to play along.

“Fiddlin’s” message of inclusion points mostly to the growing foothold young women have gained in this very traditional, very white and male-dominated form of music, music that reflects “the first American frontier,” where Scots-Irish farmers moved after coastal America had already been settled.

But the film also does a decent job of capturing the music’s centuries-old connection to a place, to this being the music of working class folk who have played through prosperity and hard times, clinging to a passion that they seem tickled to share with those just now plunging into it with them.

MPAA Rating: unrated

Cast: Ivy Phillips, Presley Barker, Kitty Amaral, Wayne Henderson, Jon Lohman, Samantha Amburgey, Martha Spencer, Jake Krack, Ronald L. Tuck and Eli Wildman

Credits: Directed by Julie Simone, script by Janice Hampton, Julie Simone, Vicki Vlassic. A Utopia Release.

Running time: 1:32