Sixty years ago the world's first rock concert was staged in Cleveland by two men whose passion for music bridged the racial divide in a segregated US.

Jimmy Sutphin was playing poker and drinking beer in a hotel room with some hockey team pals when they heard the commotion outside.

Peering out of the fifth-floor window, they saw thousands of people besieging the indoor arena across the road.

The 20-year-old student and his friends abandoned their card game and piled downstairs to investigate.

It was Friday evening, 21 March 1952, in Cleveland, Ohio, and they were about to witness history being made.

The crowd was angrily demanding entry to a performance featuring a radical new music movement that was about to sweep the nation.

Pandemonium

The world's first ever rock concert - the Moondog Coronation Ball - was about to end in turmoil after it had barely begun.

Image caption Audience members were apparently surprised to discover Alan Freed was white

The years seem to peel away from Mr Sutphin, now a 79-year-old grandfather, as he stands outside the former site of the Cleveland Arena, remembering.

"The crowd were screaming, 'let us in', and banging on the doors," he recalls. "It was chaos.

"Turns out the place was sold out and they had closed the doors on them. And these people had tickets and were not happy.

"The doors had a glass centre panel and they ended up breaking them so they could get into the building."

When police captain Bill Zimmerman arrived with dozens of officers, he was confronted by pandemonium.

Gatecrashers had stormed the 9,950-seat venue and it was dangerously overcrowded.

'Race records'

The musicians, who are thought to have only performed several songs, were ordered to stop playing as police waded into the mob. A man was stabbed in the melee.

The next morning, Mr Sutphin remembers entering the Cleveland Arena, which his father built, to find it strewn with whisky bottles.

MOONDOG CORONATION BALL Headlining was Paul Williams and his Hucklebuckers

Supported by Tiny Grimes and his Rockin' Highlanders

Also up were the Dominoes and Varetta Dillard

Tickets cost $1.50; gig was billed "most terrible ball of all"

John Soeder, music critic for the Cleveland Plain Dealer newspaper - which carried a front-page story on the tumultuous event the next day - says the Moondog Coronation Ball was the "Big Bang of rock'n'roll".

But it might not have been possible without two visionaries who raided the airwaves with this pulsating, insurrectionary new sound, and in doing so brought black and white kids together to dance in post-war America.

One of them was the concert's MC, Alan Freed. The other was Leo Mintz, owner of a music store on the fringes of Cleveland's black community.

Mintz had noticed an increasing number of white teenagers sifting through his extensive collection of rhythm and blues tracks by African-American artists.

But the singles were often a turn-off for such buyers because the industry marketed them as "race records".

And it wasn't just west-side white folk who viewed these juke-joint tunes as undesirable.

Terry Stewart, president of the Rock and Roll Hall of Fame and Museum in Cleveland (which has a permanent exhibit dedicated to Alan Freed), says: "These songs were filled with double entendres, lyrics like, 'she just loved my 10-inch record of the blues'.

"Many of the churchgoing black families were just as upset as the white families with this music being played for their children."

However, when Mintz listened to this raucous sound - with its thumping back beat, locomotive rhythm, and infectious 12-bar blues melodies - he heard the future.

Old blues euphemism

Mintz convinced Freed - a friend and onetime radio broadcaster from orchestral dances in Akron, Ohio - that the obscure tracks deserved some airtime.

Viewpoint My dad didn't invent rock'n'roll. The music was there already - he was a midwife at its birth. But he also helped bring up the child and defend it. There were a lot of people who wanted that music to disappear as it became more popular. They called it jungle music. It was seen by many as a threat to white America. This was a pre-civil rights era when most black performers couldn't even stay in motels when they took their shows on the road. You can't control art and this art was seen as dangerous. My dad, in playing this music, helped break down racial barriers that had existed for a long, long time. He was the Pied Piper of rock'n'roll. But his motivation was never to make money; it was to spread the gospel of rock'n'roll, to bring together people of diverse backgrounds for one reason: to enjoy the music.

His son, Stuart Mintz, says his father told Freed the "kids are rocking and rolling in the aisles to these records, but they won't buy them".

Mintz helped Freed, then a humble sportscaster, secure a new show on the city's WJW radio in 1951, devoted to playing this underground music.

Freed would coin the term rock'n'roll - an old blues euphemism for sex - to describe the tracks.

Using the on-air alias King of the Moondoggers, he would ring a cowbell, drink beer and howl in tribute as he played the records, while pounding out the beat with his fist on a phone book.

The flamboyant Freed's late-night show caused a sensation with black and white listeners alike.

Mintz and Freed's logical next step was to stage a live concert featuring the edgy new acts.

Headlining the Moondog Coronation Ball that night 60 years ago was Paul Williams and his Hucklebuckers, supported by Tiny Grimes and his Rockin' Highlanders, the Dominoes, Varetta Dillard and Danny Cobb. Tickets were $1.50.

One of the few photos from the event shows the men in flannel suits, saddle shoes and fedora hats, while the immaculately coiffed women wear dresses with pinched-in waists and high heels.

It is all a far cry from the ripped jeans, merchandise T-shirts and untamed hairstyles sported by rock fans of later years.

Disastrous printing error

Mr Stewart says that when Freed appeared on stage that night there was uproar.

There was a full-blown riot - the fire department opened up hoses on the crowd Stuart Mintz, Son of Leo Mintz

The predominantly black audience apparently could not believe the exuberant radio personality whose show they had been tuning in to for nine months was white.

The delighted crowd "went nuts", says Mr Stewart.

He adds: "The fact that this many people would show up for an all-black rhythm and blues event, based solely on advertising on a late-night radio show, and tear the doors off an arena to get inside, made promoters and record labels say, 'wait a minute, something's happening here.'"

Less well known is the reason why the Moondog Coronation Ball ended in disaster: a minor printing error.

The mistake was caused by someone forgetting to add the date to tickets issued for a follow-up ball, which Mintz had set about organising immediately after the initial one sold out.

As a result, an estimated 20,000 people showed up on the same night for the first concert - at a venue which could hold half that number.

Rock devil knocking

Mintz was on holiday that Friday in Florida when he was informed by an afternoon phone call of the ticket foul-up.

Image caption Alan Freed's TV show was cancelled after Frankie Lymon (centre) danced with a white girl on stage

Stuart Mintz says: "My dad was told, 'there's an emergency, you'd better come home right now', and he took a plane.

"By the time he arrived [at the Cleveland Arena] there was already a full-blown riot.

"The fire department opened up hoses on the crowd. He just tapped the cab driver on the shoulder and said, 'find me a bar.'"

The concert that was billed on a promotional poster as "the most terrible ball of them all" had certainly lived up to the pre-show hype.

Freed narrowly escaped criminal charges, although the event's notoriety helped propel him to stardom.

Younger generations raised on rap videos might well be perplexed at the idea that rock'n'roll could have once made the authorities squirm with unease.

But this was a dozen years before the Civil Rights Act. J Edgar Hoover's FBI would place Freed under surveillance because the records he played were deemed such a threat.

As broadcast historian Mike Olszewski says: "Back then, it seemed, the United States was always looking for new enemies.

"It was the beginning of the Red Scare. In 1948, you had Roswell and the UFO scare.

"People were always looking for a devil and rock'n'roll was a devil that came right into their homes."

A new era

Freed's downfall would be just as sudden as his meteoric rise to fame.

Image caption The Moondog Coronation Ball laid the foundations for every rock gig, from Woodstock to Glastonbury

In 1957, the trailblazing DJ's nationally televised rock'n'roll show on the ABC network was cancelled after a black performer danced with a white girl on stage, outraging Southern affiliates.

Freed's career was finished by the payola scandal, a then-widespread practice of disc jockeys accepting gifts from promoters to play their records.

Convicted of commercial bribery in 1962, he died of complications from alcoholism three years later, aged 43.

Though Freed had been silenced, the rock'n'roll genie was well and truly out of the bottle. The Moondog Coronation Ball laid the foundations for every rock gig that followed, from Woodstock to Glastonbury.

The Cleveland Arena was demolished in 1977 and an American Red Cross office block stands today at the spot where a new era of live entertainment was born.

Recalling how he came to be a bystander to the dawning of a new era on Euclid Avenue six decades ago, Mr Sutphin says: "Who would have thought it would be such a memorable event?"