In one of the handful of remarkable archival segments in A.J. Eaton’s mostly workmanlike documentary “David Crosby: Remember My Name,” the Beatles are holding a press conference. A journalist cries out, asking Beatle Paul who is the unfamiliar man with the soup bowl haircut hovering in the curtains behind him? It’s American folkie David Crosby, not for the last time inserting himself into an iconic moment of cultural change, like a prototype Forrest Gump.

The Gump analogy could hold for much of Crosby’s musical career. He is persistently present at the creation in contexts like the Woodstock Festival and Monterey Pop, but his prodigious musical gifts could seem dwarfed in the moment by legendary collaborators. He was critical to the harmonizing of the mid-1960s era Byrds, and he wrote “Everybody’s Been Burned” for them–the fully realized harbinger of all his dreamy jazzlike mood pieces to follow. But even Crosby admits the Byrds was Jim McGuinn’s band, and Gene Clark was the original line-up’s most prolific and noteworthy songwriter.

In Crosby, Stills & Nash, he grabbed top billing. But it was many-handed bandleader Stephen Stills who established CSN’s instrumental identity, and ex-Hollie Graham Nash wrote virtually all the big hits.

Crosby’s weird tunings and scat-derived vocalizing made him what he calls “the only member of Crosby, Stills and Nash never to have a hit.” But then Stills’ former Buffalo Springfield band mate Neil Young was invited into the fold, and Crosby couldn’t even claim to be the most idiosyncratic musician in his most iconic band.

Still Crosby persisted–partially out of a sheer cussedness amply on display in the “Remember My Name” interviews conducted by Eaton and his storied producer, ex-rock journalist Cameron Crowe, but mostly out of what can only be called an abiding love of music. And the music has loved Crosby right back. Time has been very good to Crosby’s output. His first solo album, 1971’s “If I Could Only Remember My Name,” is held in higher critical regard today than almost anything produced by CSN, while his recent renaissance–four amazingly good albums created within just the last four years, a more than doubling of his solo output–is a shimmering coda unmatched by any musician of his era. Stills, Nash and Young included.

That regenerative coda could be the subject for an amazing documentary, with Crosby teaming up with much younger alt-jazz artists like Snarky Puppy’s Michael League and Becca Stevens for the most musically sympatico collaborations of his long career. But Eaton and Crowe seem vaguely baffled by the gale force of Crosby’s second wind. Despite some tantalizing recent concert footage presented so everyone not named David Crosby is anonymized, they mostly ignore Crosby’s resurgence. They’re too busy slotting his life into a tediously archetypal baby boomer narrative of hippie liberation followed by betrayed idealism and shattered dreams to make much space for the elephant in the room: Crosby’s talent, undimmed by time, scandal and broken relationships, and rampaging away just offscreen.

Just how badly an opportunity has been muffed is illustrated by a single title card late in the doc stating Crosby recorded an entire album of new music with younger musicians during a break in filming–full stop, end of discussion. That record, which Eaton and Crowe were ideally positioned to document, is called “Here If You Listen” and it might be the best thing Crosby’s ever done. Need convincing? He’s posted the whole thing to his YouTube channel, where you can listen to it for free.

The raw facts of Crosby’s story slot almost too easily into a Headliners and Legends/Behind the Music scandelsheet format. Despite his prominent role in two gamechanging American pop bands, Crosby squandered both his fortunes on a notorious drug habit and landed in state prison, where his withdrawal from heroin and cocaine was accomplished cold turkey as part of a punishment that saved his life.

It’s grown very tiresome to watch 60s rock stars wax poetic about the good old days and the bad old drugs, and Crosby, to his credit, is a reluctant participant in anything resembling nostalgia. When Eaton takes him to pivotal locations of his musical life like the former home of Ciro’s nightclub in Los Angeles or the Laurel Canyon house where CSN first harmonized together, Crosby is both cantankerous and moved.

A more thorough and less celebrity-driven documentary might have made room for the impact of Crosby’s son James Raymond on his musical rejuvenation–another great story left untold. Abandoned by a pre-fame Crosby when his mother became pregnant in the early 1960s, Raymond grew up to become an accomplished jazz pianist and a songwriter in his own right. Raymond didn’t meet his father until 1995. He then became the de facto musical director not only for Crosby’s solo output but for latter day projects by both CSN and Crosby & Nash.

Both Raymond and CPR, the late 1990s band he shared with his dad, go unmentioned in “Remember My Name.” That’s risible for anything pretending to be the complete story.

“Remember My Name” contains its share of emotional epiphanies, most of them achieved through the interviewing skills of Cameron Crowe. Crosby’s wife of 32 years Jan Dance startles with the clarity of her devotion, whether acknowledging the strong odds an ailing Crosby will die onstage if he continues to tour or stating out loud that she will simply stop breathing when her husband is gone. Asked directly why his primary collaborators from both the Byrds and CSNY no longer speak to him, Crosby bluntly assumes the blame by saying if it was just one of them it might be open to debate but the unanimity of their silence says it all.

As does its absoluteness, because what Crosby seems to inspire in his deepest friendships is something like the anguish of jilted lovers when friendship is gone. Seduced and abandoned by that decadent choirboy charm and a tabernacle baritone as strong at age 77 as it was at 25, Crosby’s most renowned bandmates may have shuffled out of his musical story. But despite the cliche montage “Remember My Name” goes out on of “big moments” summarizing Crosby’s career, the story itself is anything but ended so long as Crosby and his music endure.