Potsdamer Platz in Berlin is heavy with symbolism from 20th-century German history. Invigorated by the international atmosphere of 1920s Berlin, the square became more than the city's traffic hub: It was also the city's cosmopolitan and cultural center. 

But a few years later, the situation changed dramatically. Potsdamer Platz was destroyed in World War II, and Hitler evaded capture with his suicide in his bunker, located nearby. After the war, when the Allies divvied up the city, the border between East and West Berlin ran directly through the square. Potsdamer Platz became a restricted area in the no man's land along the Berlin Wall.

The significance of this location in German history cannot be overstated, especially when talking about the legendary The Wall concert performed by Roger Waters of Pink Floyd on Potsdamer Platz 30 years ago, on July 21, 1990, less than a year after German reunification .

Concerts as a shared German experience

"This is not a Nazi rally, nor a reunification convention for East and West Germany," wrote German magazine Der Spiegel in 1990 ahead of the performance of the Rock-Opera album. Instead, it would be a benefit concert of massive proportions.

The 550-foot-high and 135-foot-deep mega-stage on Potsdamer Platz took four weeks and some 600 people to build. Organizers brought in cranes that would be used to maneuver gigantic marionette figures. There were helicopters, the brass band of the Russian Red Army, and musical contributions from legends including Bryan Adams, Cyndi Lauper and the iconic rock group Scorpions.

In the song "Empty Spaces," the protagonist of the album, Pink, says: "What shall we use to fill the empty spaces where we used to talk?"

The lyric could practically be a reference to the challenges that reunited Germany faced in 1990. After so many years of separation and systemic confrontation between East and West, how would they ever communicate?

Thirty years later, the answer is clear: with a rock spectacle that presented a shared realm of experience for a country that, within a few months, would be newly reunified. Taking part were an estimated 350,000 fans in the audience and hundreds of millions of spectators watching on their TV sets at home.

Record-breaking album

It wasn't a given that the concert would be a success. In 1990, the album was already 11 years old.

Released in 1979, the album The Wall was a significant stylistic change for Pink Floyd, but one that only added to their success.

Prior to the concert in Berlin, the album had sold 19 million copies globally and been performed a total of 31 times in the US, London, and Dortmund. It had even spurred a 1982 musical film based on the album starring Bob Geldof.

Today, The Wall holds the record for best-selling double-album and has maintained a place on the list of the 30 most successful albums ever sold.

But Pink Floyd's success was also a reason for the band's demise. Roger Waters wrote most of the songs on the album, and the singer and bassist demanded full creative control. This led to disputes between the band members and Waters leaving the band in 1985.

When asked about his departure in an interview, and whether he would ever perform the rock-opera again, his answer was crystal clear: "No." He said he might think about it if the Berlin Wall fell.

Five years later, the unimaginable moment came and Waters immediately received a request. The British foundation "Memorial Fund for Disaster Relief" — established a year before to collect donations for disaster aid — was planning a benefit concert and wanted him to take part.

Memory and history as main themes

Waters put together a band to replace the former members of Pink Floyd, and 30 years ago played the legendary concert that was about much more than just music.

The idea at the heart of the concert can be seen best in Waters' "Another Brick In The Wall, Part 1," the little sister to Part 2, arguably Pink Floyd's most famous song:

Protagonist Pink sings of his father who went off to war and never returned. "Daddy's flown across the ocean, leaving just a memory."

At the concert, this memory was visualized in the form of styrofoam bricks that, along with bricks representing other memories and traumas, constructed an ever-larger wall.

"All in all it was just a brick in a wall."

While this symbolic wall of trauma and memory can have many different representations, for the 1990 concert there could only be one: 170 meters (557 ft.) long and 25 (82 ft.) meters high, the wall installed for the show in Berlin represented painful memories, biographies torn apart, and ideological self-isolation in German history.

The concert's finale can therefore also be understood as a historical group therapy session for a reuniting Germany.

At the end of the two-hour show, with the words "tear down the wall," the gigantic structure fell. The crowd went wild. 

Although the performance was plagued by power outages and poor sound quality, these were merely mild inconveniences amidst a historically significant event.

The crowd at the Potsdamer Platz and those watching at home weren't just united by a huge rock concert.  Together, once again, they'd toppled the Berlin Wall.