In the mid-1960s, a young underground band played a gig at a Catholic youth club. The promoter refused to pay the band, which decided to pursue him legally in a small claims tribunal. The magistrate found in favour of the promoter: the performance, it was held, “wasn’t music”.

Scouring the catalogue of early Pink Floyd, you can see where His Worship was coming from. Consider ‘Several Species of Small Furry Animals Gathered Together in a Cave and Grooving With a Pict’, which appeared on the 1969 album Ummagumma: the band’s bass guitarist, Roger Waters, makes a dazzling array of animal noises before breaking into a barely decipherable Scottish monologue. It’s musical in the way that, say, Question Time is.

But the band went a long way quickly. Pink Floyd’s The Wall, which has its thirtieth anniversary this month, is rightly acclaimed as one of the greatest popular music albums in history and remains the highest selling double album ever. Few bands have matched Pink Floyd’s colossal aura. The sound was big, the lighting was big and the commercial success was enormous, but most striking was the scope of the band’s artistic ambition.

Pink Floyd wasn’t just another psychedelic product of 1960s hippydom. Although the band’s early work was at the centre of the psychedelic movement, this was principally the contribution of original front-man, guitarist and songwriter Syd Barrett, whose time with the group was short and, thanks partly to LSD, tragic. The Pink Floyd of the post-Barrett era became something entirely different. With its classic albums Meddle (1971), The Dark Side of the Moon (1973) and Wish You Were Here (1975), the band left psychedelia behind to pioneer the new genres of space rock and progressive rock.

Dark Side was the high point of Pink Floyd’s artistic evolution. A study of madness, it is very much about Barrett, whose descent into insanity had a profound impact on his former colleagues. Performing ‘Interstellar Overdrive’ on a tour of the US, Barrett de-tuned all the strings on his guitar until they simply dropped off. When the band was booked to appear on The Pat Boone Show, Barrett mimed the song perfectly in rehearsal and then stood frozen once the cameras were rolling. Back in England after the American tour, Barrett began teaching the band a new song he had written, only to constantly change its melody and structure so no one could possibly learn it. In 1968, with Pink Floyd booked to play at Southampton University, the rest of the band decided Barrett wasn’t worth the trouble and didn’t pick him up for the gig.

Pink Floyd could never have reached megastardom with Barrett, but he thoroughly haunts their classic works. The album Wish You Were Here, for example, is built around a 26-minute tribute to him, ‘Shine On You Crazy Diamond’. At one point during the recording of that album, Barrett wandered unannounced into the studio. Overweight and detached, he had shaved off not only his hair, but also his eyebrows. The band members hadn’t seen him in years and were initially unable to recognise him; his state reduced Waters to tears. Barrett disappeared without saying goodbye – they never saw him again.

Dark Side stayed in the charts for 14 years in the US and, to this day, sells around 9000 copies per week there. But Pink Floyd struggled for inspiration after the album’s release, feeling there was nothing much left to achieve. The band became less collaborative and the bulk of the creative work fell to Waters, its most obsessively driven member. Waters is often thought to be a somewhat cynical, bitter character; certainly, anger pervades his lyrics after Dark Side. Wish You Were Here lambasts the music industry, which Waters saw as fake and exploitative. In Animals (1977), inspired by George Orwell’s Animal Farm, the human race is reduced to dogs, pigs and sheep. Where Orwell critiqued communism, however, Waters placed capitalism in the dock.

The Wall is the album that expresses most fully and nakedly Pink Floyd’s fixations, but it was also the endeavour that finally destroyed them. More than any previous Pink Floyd album, The Wall was a product of Waters’ creative domination and an expression of his disillusionment with rock stardom. So thorough was his control during this period that the rest of the band felt largely isolated from the work. After The Wall was complete, the group as it had existed was effectively dead. The 1982 album The Final Cut was virtually a Waters solo album. In 1985, Waters departed in acrimonious circumstances and, while Pink Floyd continued to produce albums for another decade, the band became noteworthy as much for controversy as for artistic achievement.

The Wall is one of Pink Floyd’s least characteristic releases. It contains none of their trademark 20-minute instrumental excursions. Its tones are harsh, stripped back and not remotely ‘spacey’. Although Pink Floyd often made concept albums,The Wall was altogether a more ambitious exercise: a rock opera telling the story of a rock star named Pink Floyd and his self-imposed isolation. Waters stumbled upon the idea during the world tour to promote the preceding album. Pink Floyd’s popularity meant the band was performing regularly in monster arenas, which sat uneasily with Waters’ artistic sensibilities. He grew to despise his audience. On the last night of the tour, before a particularly unruly crowd in Montreal, he halted the performance mid-song to excoriate his fans:

Oh … for fuck’s sake, stop letting off fireworks and shouting and screaming, I’m trying to sing a song! … Why don’t you just be quiet? You want to let your fireworks off, go outside and let them off out there. And if you want to shout and scream and holler, go do it out there – but I’m trying to sing a song that some people want to listen to. I want to listen to it.

Finally, in a fit of frustration, Waters spotted a fan in one of the front rows and spat in his face. Vividly aware of his alienation from his audience, Waters wished he could erect a wall to separate himself physically from them. The Wall is the cathartic expression of the unintended consequences of success; it could not have existed without Dark Side.

The Wall’s protagonist is a transparent combination of Waters and Barrett. Cynical, tortured and self-destructive, Pink is destroyed by his traumatic childhood, drugs and an exploitative music industry. Pink (like Waters) never knew his father, who was killed in World War II; his mother, perhaps overcompensating for the loss, is an overprotective, stifling influence; and an abusive schoolmaster humiliates him for his creative pursuits. Although he shows signs of rebellion (“We don’t need no education / We don’t need no thought control”), Pink ultimately internalises negative experiences as “bricks in the wall” – episodes that drive him to isolate himself from the world. As a rock star, Pink is disillusioned by both the inhumanity of the music industry and the unfulfilling hedonistic lifestyle on offer. He retreats almost entirely into himself, as Barrett did: “I don’t need no arms around me … All in all you were all just bricks in the wall”.

Isolation only compounds Pink’s mental decay. He falls into insanity while continuing to be exploited by his record company. ‘Comfortably Numb’ recalls the time Waters was aggressively medicated and forced onstage, despite his being extremely ill, because a performance was scheduled. In Pink’s case, the result is a thoroughly deformed character: megalomaniacal, he embraces fascism and inspires his fans to adopt his bigotry. In 1982, when Pink Floyd turned The Wall into a film, Pink appears at this point with his eyebrows shaved – a reference to Barrett at the recording studio.

Waters is critiquing the fanatical devotion fans show rock stars, but he’s also making a more subtle point: Pink becomes the embodiment of everything that has oppressed him, adopting the fascist ideology that killed his father, as well as his schoolmaster’s intolerance of diversity. For Waters, monsters are creatures of circumstance. Pink’s schoolmaster had a “psychopathic” wife, who nightly “thrash[ed him] within inches” of his life; the oppressed takes on the colours of the oppressor. Thus, transposed into a different key, the melody that drives “We don’t need no education” becomes the theme for the schoolmaster’s fascist excursions. There is an inevitable, tragic circularity to The Wall. The last song becomes the beginning of the first; the album ends with a spoken voice interrupted mid-sentence, and it begins with the completion of that sentence.

Perhaps, though, Waters’ vision has a redemptive streak. Pink comes to recognise the monster he has become, ultimately rejecting fascism and tearing down the wall. Also, the final track suggests Pink would have found affection from the world if only he’d been open to it. To this extent, the album seems to be making a humanist argument, rejecting the intense desire for isolation that Waters felt. But is it too late for Pink to become a compassionate person, ready and willing to connect with the people in his life? Is the mix of fame and alienation that a celebrity experiences irredeemably dehumanising? Is humanity destined to reproduce its degrading cycle of oppressor and oppressed ad infinitum? The album is ultimately unclear on these questions. But still, it’s probably best to let Waters speak for himself:

All alone or in twos
The ones who really love you
Walk up and down outside the wall …

And when they’ve given you their all
Some stagger and fall
After all, it’s not easy
Banging your heart against some mad bugger’s wall.