Dr. Michael White, the traditional New Orleans jazz clarinetist, is a virtuoso at his craft. If a new documentary film called City of a Million Dreams receives as wide an audience as it deserves, White will become a national folk hero.

City streams online Aug. 11-22 at the Rhode Island International Film Festival and will play at film festivals and academic settings throughout the fall. It is a work a quarter-century in the making by renowned New Orleans journalist and cultural chronicler Jason Berry. It shares the same name and similar themes as Berry’s 2018 hardcover history released to coincide with the 300th anniversary of the city’s founding, but the film is less a chronological narrative than it is a collage of contrapuntal and syncopated sounds and images revolving around New Orleans jazz funerals.

Yes, funerals — as in the famous joint expressions of mourning and celebration that feature “second line” dance marches to mark the joy of a soul’s ascent into heaven. As director Berry shows, those ceremonies have extraordinarily complex roots and meanings. What his documentary does, lovingly and in mesmerizingly watchable fashion, is explore the African American culture from which jazz funerals evolved — and how the funerals epitomize the soul and resilience of the Crescent City perpetually endangered by storms, floods, fires, coastal erosion, and diseases such as Yellow Fever.

Mardi Gras, of course, plays a prominent role in the collage, as do the far darker legacies of slavery and Jim Crow and the sad reality of some urban gang warfare. And Hurricane Katrina blows through the film with tremendous emotional force. Without an obvious, driving, central narrative, sometimes the film doesn’t seem to be going anywhere in particular (although it is), but even when it spins off as if to mimic the improvisational style of jazz, its visual and auditory richness keeps the viewer enthralled.

From all of this, half a dozen or so people emerge in lead roles, with three the most prominent: the late, irrepressible jazz impresario and raconteur Danny Barker; the adopted New Orleanian blogger/cultural aficionado Deborah “Big Red” Cotton, who serves at times as a narrator and at times as an interviewee; and, as the intellectual and narrative center of it all, the aforementioned Michael White.

White is the most prominent of a group of then-younger musicians recruited by Barker in the late 1960s/early ’70s to keep the traditional New Orleans style going for new generations as Barker’s own contemporaries faded away. (White’s friend, the wonderful trumpeter Gregg Stafford, is another onetime Barker recruit who also features prominently in City.) White’s own family has deep New Orleans jazz roots, but White was classically trained before falling in love with the city’s unique sound. A former professor of Spanish who now is an endowed chairman in jazz studies at Xavier University in New Orleans, White is also a renowned jazz historian. Soft-spoken and eminently approachable in person as well as on camera, White exudes an extraordinarily winsome love not just for the music but for the culture surrounding it.

White also possessed perhaps the world’s single greatest private collection of old jazz records, sheet music, and other jazz-related artifacts — not just knickknacks but recognized historical treasures. Then Katrina hit. His house was in a low-lying area near the London Avenue Canal, whose floodwalls were among those infamously breached during the tempest. Weeks later, Berry, camera in tow, accompanied White on White’s first post-Katrina return to the house, not knowing what he would discover. What they found was pure ruination: the loss of some 5,000 early LPs, original sheet music from Jelly Roll Morton, and so much more.

In achingly poignant fashion, Berry’s film shows the physical damage, the emotional toll it took on White, and White’s resolute, soul-searching recovery and the reinvigoration of his creative genius. Since Katrina, White has produced numerous, richly listenable albums of mostly original compositions, although occasionally his band might whimsically record a trad-jazz version of a 1960s folk-rock song by, say, The Turtles.

All of this provides a perfect thematic echo for the documentary’s jazz funeral motif. Berry shows the funerals as elaborate representations of what narrator Deborah Cotton calls the city’s “two faces, just like the Mardi Gras masks: tragedy and comedy.” As described by Bruce Raeburn, the longtime curator of the Hogan Jazz Archives at Tulane University, “New Orleans has always been a hazardous place to live. It’s hard to survive here.” Yet, says another interviewee, “Return again in another life, and it will be jubilant.”

So here are the funerals’ historical beginnings in the onetime slave gathering-ground known as Congo Square. There is the colorful, exquisitely artful tradition of the “Mardi Gras Indians,” which actually are black social organizations. And over yonder are tiny tots blowing on horns, young men dancing on rooftops, mourners prone on their bellies in church aisles, tuxedo-clad musicians followed by thousands in T-shirts and ill-fitting shorts, perhaps a horse-drawn carriage and a congresswoman — and always, always, such a sense of the exotic as to be deliciously disorienting.

“New Orleans lured me from my dark, brooding funk,” Cotton said, “and tossed me into the fire of dancing black folks and brass instruments. I began to feel alive again.”

White said that in the course of 40 years, he has played in probably 200 full jazz funerals. Many of them were for fellow musicians, others for leaders of black “social aid and pleasure clubs.” Another, lovingly recorded by Berry, was for noted civil rights attorney Lolis Edward Elie (whose son, Lolis Eric Elie, is himself a journalist, screenwriter, cookbook author, and chronicler of southern barbecue traditions). Like a trad-jazz tune, all these funerals emphasize recurring themes, but each iteration is improvisationally unique.

Berry’s documentary brilliantly captures all this and more. It is a starkly realistic but joyous homage to a culture and a sound that were generations in the making, with eternity in mind. And, without giving away the ending (for those unaware, as I was, of the details of a particular storyline included in the film), let it be said that for viewers who crave emotional catharsis, City of a Million Dreams provides it in unforgettable fashion.

Deborah Cotton’s narration gets the last word when she says of her adopted city that it “breaks your heart until you are crying on the kitchen floor. She haunts you, melts you, and is just a damn joy to live in.”

Likewise, this film is just a damn joy to watch.