In every great rock biopic, there’s a defining sequence of ecstatic musical fire that does two things at once. For openers, it gets your blood racing at the song you’re hearing. (With each electrifying note, it demonstrates why the star we’re gawking at deserves to have a movie made about him.) But the other dimension of a great rock-biopic music sequence is that the drama we’ve been watching — the story of who the star is, off-stage, as a human being — gets poured right into the excitement of his performance.

That’s what happens in “Ray” when Jamie Foxx’s Ray Charles does “What’d I Say” in a nightclub, his rolling percussive piano cadences pushing the song forward into a momentum that keeps building, like gospel with a meaner bolder engine throttling it along; that engine is the dominating heat of Ray Charles’ lusty life force. It happens, as well, in “Sid and Nancy” when Gary Oldman’s Sid Vicious, his voice a-quaver, his eyeballs dancing up into his forehead, launches his solo moment as a post-punk psycho rocker by walking down a lit-up Vegas stairway snarling “My Way” into the camera, remaking the Sinatra standard into a vintage expression of his own f—k-everything nihilist joy.

At moments like these, we’re not just sitting back and watching an actor play a famous music star — we’re fusing with his larger-than-life aura. That’s the vicarious thrill and glory of a great rock biopic.

In “Bohemian Rhapsody,” the always watchable but never as good as it could have been biopic about Freddie Mercury and Queen, you could say that the defining sequence takes place at the end, when the film culminates in a song-for-song, move-for-move re-enactment of Queen’s reunion set at the 1985 Live Aid concert in Wembley Stadium. Rami Malek’s Freddie preens and swaggers and croons; he owns the stage and, for about 20 minutes, the world.

Except that the drama, at that point, is built around a glaring biographical distortion. The film says that Freddie was already ill with AIDS, when in fact he wasn’t diagnosed until two years later. Leaving aside the ethics of that kind of manipulative inaccuracy, the result of the change is that it turns the Live Aid sequence into the story of Freddie Mercury’s plucky resilience and show-must-go-on bravura — good qualities, to be sure, but not necessarily the ones that the movie was about. Besides, the Live Aid sequence arrives nearly two hours into a two-hour-and-18-minute film. As satisfying as it is to watch, it comes a little late to be the defining moment of who Freddie Mercury was as a rock star.

The other sequence of “Bohemian Rhapsody” that could qualify as its signature rock centerpiece is, of course, the elaborate recording of the title song. It’s presented as Queen’s rebellious epic of studio mischief, and we see them tape assorted pieces of it (like the falsetto Galileos), which gets us onto the whole shoot-the-works manic wavelength of the thing. But mostly we see Brian May (Gwilym Lee) doing several takes of his snaky mid-song guitar solo, which is a little bit of an odd thing to focus on, given that the essence of “Bohemian Rhapsody” as a song is that it’s a divinely cracked Freddie Mercury aria. The recording sequence is fun, but it doesn’t exactly leave you awed at the thrilling eccentricity of Freddie’s passion.

Nothing in the movie does — at least, not until the Live Aid sequence, which is designed to send you home happy (and succeeds). At that point, however, you may realize that “Bohemian Rhapsody” has never quite come up with a sequence in which Freddie, on stage, discovers the essence of who he is — and the audience discovers it right along with him. That sequence would had to have come much earlier, around 1974 or 1975, when Freddie first fused the thunder-god strut of Robert Plant with the glam insolence of a pop diva whose voice soared into the stratosphere.

That’s when Freddie found his transcendence as a rock star, and the figure he was off-stage fed into it: flamboyant, erotic, insatiable, a gay man who craved adventure but covered every track — and who, maybe because he was hiding his identity from the world, found a lot more pleasure than romance. That’s a lonely position to be in, and I always felt that Mercury expressed it when he sang “Somebody to Love,” albeit it with a wink of celebrity irony. That great and gorgeous song says, “I’ve never found love, and it’s driving me crazy.” But it also says, “God, I love looking for it!”

That’s the Freddie Mercury “Bohemian Rhapsody” should have been about, the one who turned his hunger and desire into rock ‘n’ roll deliverance. But from almost the moment that Queen comes together as a band, Freddie is just there, fully formed, kicking out their greatest hits. The way Rami Malek plays him, he’s a great showman (maybe the greatest showman), but there’s no deep personal thrust to what he’s showing. The film is an exuberant and innocuous jukebox musical that might have been made for people whose primary association with Queen is to the head-bangers of “Wayne’s World.”

That probably sounds like carping, but to be clear: It’s precisely because I love Freddie Mercury and Queen so much that I’m haunted by the movie “Bohemian Rhapsody” could — and should — have been. I’m haunted because the rock biopic is a genre that, over the years, has yielded up a handful of extraordinary films, and they have set the bar high.

It wasn’t always that way. Back in 1978, a lot of people were pleased to discover that a biopic like “The Buddy Holly Story” could be as decent as it was. It was nothing more than a friendly, bopping little B-movie, and you could tell that a lot of it was made up, but Gary Busey, skinny and charmed in oversize horn-rims, gave the film all the authenticity it needed. “The Buddy Holly Story” was rote and conventional, but it was revved, and that, at the time, seemed more than enough.

The movie that set the new standard for rock biopics was Alex Cox’s “Sid and Nancy.” Made in 1986, it was the definitive punk movie, and one of the greatest films of the ’80s, and part of what made it brilliant was that it caught how Sid Vicious’ spiky annihilating circus-freak insanity was of a piece with the madly energized theater of punk. The Sex Pistols’ music was a declaration of not giving a f—k (“No feelings…for anybody else!”), and Sid Vicious hardly gave a f—k about himself. Yet in showing you how even this razor-carved wastrel could fall in love with someone (Chloe Webb’s junkie heartbreaker Nancy Spungen), the movie punked its own inhumanity. It turned self-destruction into rock ‘n’ roll tragicomedy.

Since then, there have been a handful of true-life rock dramas that have met the gold standard of cathartic authenticity. That doesn’t mean that every moment in them is real. It means that they take the music we know and the life we probably don’t and fuse them into a mythology that channels the spirit and essence of a great artist.

Tate Taylor’s “Get On Up” (2014) was the first movie to reveal that Chadwick Boseman has the potential to be the finest actor of his generation. It tells the story of James Brown (and is actually extremely accurate about his life), and Boseman plays him with a virtuosity that brings his every gravity-defying stage move, and prickly emotion, to life. The movie is pure bliss — the richest drama of the classic rock era (or, in this case, the funk era) ever made. And in “Love & Mercy,” the producer-turned-director Bill Pohlad brought off a minor miracle: He took the delicate, damaged, moonstruck figure of Brian Wilson, who created some of the most beautiful music of the 20th century, and he made you feel you were literally witnessing what it was like when Wilson led the Beach Boys in recording “Pet Sounds.” Paul Dano’s performance was as pure an act of channeling as you’re likely to see, and though John Cusack, who in the film’s other sections played Wilson in the 1980s, didn’t look as much like him, the movie caught the private incandescence of a lost soul trapped, at times happily, in the cocoon of his genius.

These are movies that will stand the test of time. So will “Backbeat,” Iain Softley’s extraordinary 1994 drama about the Beatles before they got famous. “Bohemian Rhapsody,” on the other hand, is a highly watchable piece of product. It’s a spin-through-the-greatest-hits lark that never delivers that decisive sensation of rock ‘n’ roll truth. That said, its success is likely to kick open some doors. Most of the rock legends of the ’60s — Janis, Jimi, etc. — never got the lavishly scaled biopics people kept trying, and failing, to make about them. It’s almost as if we didn’t believe that mere actors could live up to the icons. (That said, “The Doors” is a flawed but pretty damn good movie.)

But now the rock biopic is having a ‘70s moment. “Rocket Man,” the Elton John story, is due next year, with the trailer already in theaters, and after that film (if it’s successful) and “Bohemian Rhapsody,” there’s a vast landscape of legends just waiting to be mined. We can all choose our favorites. Going back to the ’60s, I’d love to see an indie director like Todd Haynes take on a classically made biopic about the Velvet Underground. (Now that Lou Reed has passed on, it could actually get made.) But more than anything, I would crave — done right — the Led Zeppelin story. It’s got everything: monumental ego clashes, the ultimate in decadent backstage ‘70s rock-star excess, and the most fantastic soundtrack a rock drama could hope for. The title? Call it “Been a Long Time.” But going forward, maybe the following principle should be in play. If you’re going to do a rock biopic about a genuinely great band (or solo artist), don’t just make it an okay, fun, acceptable movie. It’s got to be something more — a stairway to heaven.