Paul McCartney belting out a rock and roll standard leans into John Lennon, who grins manically. George Harrison strikes a flamboyant stage pose with his arms outstretched and Roy Young is clearly having the time of his life on the piano.

The black and white photograph shows the Beatles — fronted by John, Paul, George and Roy — when they were really a hot live act.

That’s right! Roy not Ringo — Roy Young from Oxford — not a name that readily springs to mind when you think of the Fab Four.

But there he is, totally at home on stage next to John, as well he might be. For Roy Young was not making a one-off guest appearance with the Fabs. He was by then a fixture — performing night after night with the Beatles in Hamburg, adding keyboards and backing vocals to their raw but already compelling sound.

Roy performed with the Beatles over several weeks in the Star Club, as the band’s years in Hamburg (where they played more than 300 nights) drew to a close exactly 50 years ago.

Soon they would be heading back to England, to Abbey Road studios. You know the rest.

As a claim to fame, what can top performing with the Beatles, before the suits and screaming, when they rocked on stage like they would never do again?

But there is more.

Sitting in his living room in Kingston Bagpuize looking through old photographs with his wife, Carol, Roy tells me he could have been a Beatle himself, but he declined the invitation to head back with them to England.

“I remember coming off stage one night and Brian Epstein, the Beatles’ manager, was standing at the side of the stage,” he recalls. “Brian said, ‘may I have a word? The lads asked me to ask if you would be interested in going back to England and join them to get a record contract’.

“I told him it was an incredible offer but I would have to think about it. If I had been smart enough there is no doubt what I would have done.”

Instead, Roy says, he took the decision to stay in Hamburg.

“I went back to Brian and said ‘I’m going to decline your offer because I’m under contract with the Star Club’. I could have got out of it. But I’d walked out of the Top Ten Club (another Hamburg club in the Beatles story) and I thought ‘I just can’t do it again’.

”Yes, it could have been the biggest move of my life. I became so sick of being asked how I felt about walking away from that, that I had to come up with an answer. I say, ‘well every night before I go to bed, I go into the bathroom and hit my head on the wall 10 times’.

“Paul and John both loved my voice. I was then known as the English Little Richard. They used to watch me on television and my show. I guess I was the only one doing that kind of thing then.”

You can see why McCartney and Lennon were impressed. He had been evacuated to Oxford from London at the start of the war and played the piano from the age of eight. After leaving South Oxford School in St Aldates he gave his first professional performance at the Carpenters Arms in Cowley. His mother had been a well known pub pianist.

After serving in the merchant navy, he auditioned for the new pop show Oh Boy, later touring with Cliff Richard before heading for Hamburg.

He recalls his taxi pulling up outside the Top Ten Club and being met by a deputation of the band.

“John lifted me up off the ground, then Paul picked me up. He said, ‘I’m Paul McCartney and we’re called the Beatles. We’ve finished playing here but when we heard you were coming we wanted to stay on for the opening night’.”

They later took him to a coffee bar to give him a briefing on surviving Hamburg, where musicians survived on a diet of pills. But the real key, he was told, was staying on the right side of the bouncers and bar staff. Later, with Tony Sheridan and Ringo Starr he formed Beat Brothers, Top Ten Club’s house band.

After moving to the Star Club, he was responsible for enlisting talent such as Chuck Berry, Gene Vincent and Little Richard.

He personally drove up to Liverpool to persuade Brian Epstein to allow the Beatles to return for another stint in Hamburg, where they had built up a massive following.

Roy admits to being a massive fan himself, playing on their first recording sessions with Polydor in Germany.

“Paul, John and George were all geniuses. For me it felt like they were finding how they could adapt themselves into becoming a unit. It was wonderful to have the opportunity to see it happening. There was definitely a thing, an aura around them.

“I remember doing some songwriting with John and Paul. It ended up with screwed-up paper all over the floor. I often wonder what that would be worth now.”

Tomorrow night, he will get to relive those times, when he will be headlining a concert in Hamburg to mark the 50th anniversary of the Star Club.

Those memories extend to driving the Beatles to the seaside where they all plunged into the sea still wearing their leathers.

“I ended up in the water. I looked up and was horrified to see my car being driven into the sea with John at the wheel. He was crazy, a real Jekyll and Hyde. You could be out all night with him having great fun. And the next day he would be someone else.

“But he was a lovable guy. All the girls said they liked Paul. But if you were in a room with him for half an hour, you’d fall in love with John.”

Back in England Roy had a hit with a Lennon-McCartney song Got to Get You Into My Life, after joining the Brian Epstein-managed Cliff Bennett and the Rebel Rousers.

To author Trevor Hayward, who wrote a book on Oxford’s 1960s music scene, Roy Young was “Oxford’s first true superstar”.

Young fans certainly included David Bowie, who asked the boogie-woogie man to join him in Paris to play on the album Low.

“When I took the call from David I was in the Speakeasy Club. I remember saying, ‘I’m definitely not wearing tights — I was born a cowboy’.“ He recalls Bowie joining him in a heavy gin-drinking session in the studio. After announcing that he was ready for bed, the Thin White Duke tumbled down a steep flight of stairs.

“He came in the next day and his back was black and blue. His manager said, ‘you nearly killed him’. It was one of those where if he had not been so drunk, he might well have died in the fall.”

Later he joined Bowie’s one-time side-kick Mick Ronson and Ian Hunter, of Mott the Hoople fame, on an American tour.

His move to the United States was to mean reluctantly turning down a Beatle a second time.

“Paul rang out of the blue and asked if I would go down and teach Linda to play keyboards.

“I told him I would have loved to, but I was going to America.”