Every time someone says the Beatles are the greatest band in history, the automatic response is a condescending smile. Sure: it’s your parents’ music, it’s nostalgia, it’s the cultural myth on repeat, it’s that you haven’t listened to enough music. And then comes the list of objections. The Stones had more edge. Dylan was a better lyricist. Led Zeppelin were better players. Any jazz combo from the fifties had more harmonic sophistication than the entire Lennon-McCartney catalogue. And plenty more nonsense along those lines.

All of those objections may be true, and none of them matter.

They may be true because the Beatles were indeed not the best instrumentalists of their generation, nor the deepest lyricists, nor the rawest, nor the most avant-garde in any pure sense. And they don’t matter because the greatness of the Beatles lies in none of those individual parameters. It lies in something far rarer and far harder to articulate: the combination of everything. The density of invention sustained over time. The ability to reinvent themselves with every record without ever losing quality or identity. Nobody else did that. Not before, not since.

This is not an opinion. It is very nearly an empirical fact. And it can be argued with rigour, without fanaticism, without nostalgia, without the defensiveness of a fan. It can be argued the same way one argues that Shakespeare is the greatest dramatist in the English language or that Bach is the most complete composer in the Western tradition: not because it is impossible to dispute but because the evidence is so overwhelming that the burden of proof falls on the one disputing.

The argument begins with a fact. Between 1966 and 1970, the Beatles released Revolver, Sgt. Pepper’s Lonely Hearts Club Band, Magical Mystery Tour, The Beatles (the White Album), Abbey Road, and Let It Be. Six studio albums in four years.

Stated like that, it doesn’t sound particularly impressive. Plenty of bands released six records in four years. In the sixties it was normal: labels demanded an album every six months, sometimes more. What makes these six records unique is not the quantity but what they contain. Each of those albums, taken on its own, would have been enough to define the entire career of any other band in history. Together, in sequence, they constitute something without equivalent in any popular art form of the twentieth century. Not in music, not in film, not in literature.

I’m going to do something that may seem tedious but that I think is necessary: go through each one briefly, not as a fan but as though building a legal case. Because the argument for the Beatles’ greatness does not rest on emotion. It rests on evidence.

Revolver, 1966. A record containing “Eleanor Rigby,” “Tomorrow Never Knows,” “For No One,” “Taxman,” “Here, There and Everywhere,” “I’m Only Sleeping,” and “Got to Get You into My Life.” Seven songs that on their own would be enough for a career. But they are not a greatest hits collection. They are a cohesive album that moves from music hall to musique concrète, from soul to raga, without anything sounding forced. This is the record where pop music lost its ceiling.

Sgt. Pepper’s Lonely Hearts Club Band, 1967. The most famous album of the twentieth century, with everything that implies, both genuine and inflated. People say Sgt. Pepper’s is overrated, and they have a point: its reputation owes as much to cultural impact as to musical quality. But even discounting the mythology, even listening to it as just another record, what remains is “A Day in the Life,” which is one of the ten best songs ever recorded, plus “She’s Leaving Home,” “Lucy in the Sky with Diamonds,” “Getting Better,” “With a Little Help from My Friends,” “Being for the Benefit of Mr. Kite!” The final orchestral passage in “A Day in the Life,” those forty bars of controlled chaos resolving into the most famous piano chord in history, remains one of the boldest things anyone ever did in a recording studio. George Martin arranged it by instructing each musician in the orchestra to start on the lowest note of their instrument and climb to the highest, at their own pace, all meeting on an E at the end. It is the closest pop music ever came to the compositional anarchy of Penderecki, and it appears on a record that sold millions.

Magical Mystery Tour, 1967. The odd one out, the one people tend to overlook. The film was a disaster, the Beatles’ first public failure. But the album contains “Strawberry Fields Forever,” “Penny Lane,” “I Am the Walrus,” “The Fool on the Hill,” and “All You Need Is Love.” Five songs any band would kill to have written just one of. “Strawberry Fields Forever” is probably Lennon’s finest achievement: an exercise in psychedelic nostalgia that George Martin assembled by splicing two takes recorded in different keys and at different tempos, a technical trick that should not have worked and that produced something unrepeatable. “Penny Lane” is its perfect counterpart, McCartney in baroque-pop mode, with a piccolo trumpet nobody had used in a rock song before and that after hearing it seems as though it should always have been there.

The Beatles (the White Album), 1968. Thirty songs. A double album that is intentionally excessive, contradictory, ranging from the acoustic folk of “Blackbird” to the proto-metal of “Helter Skelter,” from McCartney’s ballad “I Will” to the sonic avant-garde of “Revolution 9,” from the parodic country of “Rocky Raccoon” to the visceral blues of “Yer Blues.” People say the White Album would have been better as a single disc, tighter, more edited, and they are probably right. But that is a curator’s objection, not an artist’s. What the White Album proves is that in 1968 the Beatles had so much music inside them they could not contain it in a conventional format. The excess is the point. No other band in history could have filled a double album with that level of material, and that includes the tracks people consider minor, like “Martha My Dear” or “Cry Baby Cry,” which in the context of any other catalogue would be gems.

Abbey Road, 1969. The last album they recorded together, though not the last released. And for many of us, the best.

Abbey Road is a strange record if you think about it. A farewell album that doesn’t sound like a farewell. A record made by four people who were barely speaking, recorded in a studio where the tension was so thick that Geoff Emerick, the engineer, had quit during the White Album sessions and had to be talked into coming back. And yet it sounds like the most integrated, most fluid, most assured thing the Beatles ever put to tape.

Side B of Abbey Road is the best thing the Beatles ever did. Not the best song, not the best idea. The best thing. The medley, those sixteen minutes running from “You Never Give Me Your Money” to “The End,” passing through “Sun King,” “Mean Mr. Mustard,” “Polythene Pam,” “She Came in Through the Bathroom Window,” “Golden Slumbers,” “Carry That Weight,” is a suite in which fragments that individually would be incomplete lock together into something far greater than the sum of its parts. McCartney at the height of his powers as a musical architect, arranging pieces the four of them had brought separately into a structure none of them could have imagined alone.

And “The End” closes with something that had never happened on a Beatles record: a drum solo from Ringo followed by three alternating guitar solos from Lennon, McCartney, and Harrison, eight bars each, taking turns as though in conversation. It is the last time the four Beatles played together with the intention of making something great, and what they made was exactly that. “And in the end, the love you take is equal to the love you make.” Last line sung on the last album. McCartney wrote it in ten minutes. It is perfect.

And then there is “Something,” by Harrison, which Frank Sinatra called the greatest love song ever written. And “Come Together,” Lennon in swampy, low, faintly menacing mode. And “Here Comes the Sun,” Harrison again, a song that by all rights should be saccharine and isn’t, because the melody is so good it transcends any objection.

Let It Be, 1970. The troubled record. Recorded before Abbey Road but released after, covered in a Phil Spector orchestral production McCartney hated and eventually undid decades later with Let It Be... Naked. It is the most uneven of the six, the one that most suffers from the internal tensions, the one that sounds most tired. And it still contains “Let It Be,” “The Long and Winding Road,” “Get Back,” “Across the Universe,” “Two of Us,” and “I’ve Got a Feeling.” If Let It Be is the worst Beatles album, and it probably is, their worst album contains at least four songs that would rank among the best in any other band’s catalogue.

Now. The argument is not simply “they made a lot of good records.” Plenty of bands made a lot of good records. The Stones between 1968 and 1972 released Beggars Banquet, Let It Bleed, Sticky Fingers, and Exile on Main St., which is a formidable run. Led Zeppelin have four or five enormous records. Radiohead have OK Computer, Kid A, and In Rainbows, all masterpieces. Pink Floyd have Dark Side of the Moon and Wish You Were Here. Dylan, who is not a band but who is the inevitable comparison, has an entire decade of genius between Bringing It All Back Home and Blood on the Tracks.

The difference is not one of degree. It is one of category.

And the difference is this: none of those bands reinvented themselves with every album. The Stones found their sound on Beggars Banquet and refined it over five years, which is admirable, but it is a variation on a theme. Led Zeppelin were essentially the same band on I as on Physical Graffiti, only with better production and more ambition. Radiohead reinvented themselves once, between OK Computer and Kid A, and it was an act of extraordinary courage, but after Kid A the reinvention became a style in itself, which is another form of repetition. Pink Floyd made one transition, between the Barrett era and the Waters era, but the Waters era is fairly consistent internally.

The Beatles reinvented themselves six times in four years. From Revolver to Sgt. Pepper’s there is a leap. From Sgt. Pepper’s to the White Album there is another, in the opposite direction. From the White Album to Abbey Road there is yet another. Each record sounds as though it were made by a different band that happens to have the same members. And it isn’t that the records are inconsistent or erratic: each one is internally cohesive, each has its own logic, each works as a self-contained world. What they don’t have is a repeated formula.

This is the truly anomalous thing. In any creative discipline, constant reinvention usually comes at the cost of quality. The artist who experiments all the time eventually produces something bad, because that is what experimentation is: trying things with no guarantee they’ll work. The Beatles experimented without pause for four years and never produced a bad record. Not even a mediocre one. The weakest album in the run, Let It Be, would be the best record in almost any other band’s career.

That is not normal. It cannot be explained by talent, which is necessary but not sufficient. It cannot be explained by circumstances, which were often adverse. It cannot be explained by luck, because luck does not hold six times running. It is something that, for want of a better term, we have to call collective genius: an unrepeatable convergence of individual talents that, in combination, produced something exceeding the sum of its parts in a way that defies analysis.

A word about McCartney, who is the Beatle hardest to defend and most worth defending.

The general consensus, formed in the seventies and hardened in the eighties, says Lennon was the genius and McCartney was the craftsman. Lennon was raw, authentic, political, difficult. McCartney was melodic, commercial, pleasant, easy. It is a comfortable narrative and a deeply unfair one.

McCartney is, by volume and by consistency, the greatest melodist in popular music. McCartney wrote “Yesterday,” “Eleanor Rigby,” “Here, There and Everywhere,” “For No One,” “Penny Lane,” “The Fool on the Hill,” “Blackbird,” “Let It Be,” “The Long and Winding Road,” “Hey Jude,” “Golden Slumbers,” and the entire architecture of the Abbey Road medley. That is a catalogue of melodies without rival in the twentieth century. Cole Porter didn’t write that many songs that good. Gershwin didn’t either.

But McCartney’s reputation suffers for two reasons. The first is that Lennon died young, and dying young freezes a reputation at its highest point. McCartney’s solo career has obvious ups and downs, yes, but it also has “Band on the Run,” “Maybe I’m Amazed,” “Live and Let Die,” and many more songs proving the talent was still there, with less discipline and without Lennon’s creative tension as counterweight.

The second reason is more insidious: McCartney makes the difficult look easy. His melodies sound so natural, so inevitable, that you assume they came without effort. “Yesterday” sounds as though it always existed, as though McCartney simply found it floating in the air. And that naturalness gets mistaken for lack of depth. If it sounds easy it must be easy, and if it’s easy it can’t be genius. It is a fallacy that hurts McCartney the same way it hurts Fred Astaire, or Roger Federer, or anyone whose mastery is so complete it becomes invisible.

Lennon, by contrast, left the seams showing. His voice sounded rough, his lyrics were confrontational, his image was the artist who suffers. And there is something in modern culture that confuses suffering with authenticity: if it hurts, it must be real. McCartney didn’t fit that story. He was too cheerful, too prolific, too versatile. He wrote love songs unashamed of being love songs, and ballads that made no apology for being beautiful.

The truth is the Beatles needed both, and the tension between them, the constant friction between Lennon’s rawness and McCartney’s elegance, between the pursuit of emotional truth and the pursuit of formal perfection, is what made the band what it was. Without Lennon, McCartney would have been a brilliant but probably conventional songwriter of musicals. Without McCartney, Lennon would have been an interesting but erratic and limited artist. Together they were something neither could have been alone, and that nobody else has been.

There is one last argument I want to make, and it is the hardest to articulate because it has to do not with quality but with influence, and influence is hard to measure.

The Beatles didn’t just make extraordinary music. They invented categories. Before the Beatles, a rock album was a collection of singles with filler. After Rubber Soul and Revolver, an album could be a unified work of art. Before the Beatles, the recording studio was a place where you documented a live performance. After Sgt. Pepper’s, the studio was an instrument. Before the Beatles, rock musicians didn’t write their own songs as a rule. After the Beatles, not writing them was the exception. Before the Beatles, the music video didn’t exist as an art form. Before the Beatles, the rock concert was an entertainment event, not a cultural happening. Before the Beatles, pop music was not the subject of serious analysis by critics, academics, or classical composers.

Any one of those transformations would have been enough to secure the historical importance of whoever produced it. That all of them were produced by the same group, in a span of less than a decade, is a concentration of impact without parallel. Not even Mozart, who transformed several genres at once, generated as many structural changes in as short a time, because Mozart operated within an institutional system that limited the speed of innovation. The Beatles operated in mass culture, where changes travel at the speed of radio.

Some will say this influence is a historical accident. That the Beatles had the luck of being in the right place at the right time, when youth culture was being born, when recording technology was reaching a certain threshold, when television was globalising fame. And there is some truth in that: without those conditions, the Beatles would not have had the impact they did. But the conditions were there for everyone. The Stones were in the same place at the same time. The Kinks, the Who, the Beach Boys, all operated in the same context. And none of them transformed as many things simultaneously.

Conditions are necessary but not sufficient. What is sufficient is what the Beatles had: two of the greatest songwriters in the history of popular music working side by side, competing, complementing each other, pushing each other towards an excellence neither would have reached alone. Plus a third songwriter who in any other band would have been the undisputed star. Plus a drummer whose style was so functional and so creative that it defined what drums can do in a pop song. Plus a producer, George Martin, who had the classical training to translate the band’s ideas into orchestral arrangements and the humility to understand that his job was to serve the song, not the ego. Plus an engineer, Geoff Emerick, who was twenty years old and didn’t know the things they were asking him to do were impossible, so he did them.

That convergence does not repeat. It is not that it is unlikely. It is the kind of phenomenon that occurs once in a century, perhaps once in the lifetime of a medium, like Shakespeare in theatre or Homer in epic. Saying this is not nostalgia. It is not fanaticism. It is simply looking at the evidence honestly and accepting what it says.

The Beatles are the greatest band in the history of rock. And rock, for all its limitations as an art form, is the music that defined the second half of the twentieth century. Which makes the Beatles, if you accept both premises, the most important artists in modern popular culture. Not the deepest, not the most transgressive, not the most technically accomplished. The most important. Because they did more, better, in less time, than any other group of people making popular music.

And that is not an opinion. It is the stubbornest fact the history of popular art has to offer. People are free to dispute it, of course. But the burden of proof, at this point, lies with the one disputing.