Vadim Kozin was one of the most famous singers in the Soviet Union in the 1930s, but in 1944 he disappeared - banished to Siberia. Half a century later the British singer, Marc Almond, heard some surviving recordings and became a devoted fan. Together, he and I set out to discover the story of Kozin's long and strange life.

Marc Almond knew nothing of Kozin when he first encountered his music during a concert tour of Russia in 1992.

"I had no idea about Russia, or the Soviet Union then," he says. "We went to Siberia and Omsk and Novosibirsk. It was winter and I played in these freezing places with paint peeling off the walls, a ropey piano and one overhead lightbulb. But the audiences were just wonderful. People would come up after the show and give me what they had - a jar of jam or a bunch of flowers, or a cassette. It was magical - it opened up a new world to me."

On one of these cassettes he heard crackly recordings of Vadim Kozin's pure, distinctive tenor.

Kozin sang tango and romance - what we might call torch songs. He made his name as a stage performer but the coming of recorded music spread his fame through radio and gramophone to a vast audience and wove his songs into the cultural fabric of the USSR.

Born in St Petersburg in 1903, Kozin came from a merchant family that went out of business during the Russian revolution. His mother, Vera, was a singer of gypsy origin and Kozin became the family breadwinner at about 19, when his father died. He got a job as a cinema pianist and began to compose his own gypsy-style ballads.

We know that Kozin began to keep a journal around 1929 although almost all of it is missing, and there are very few clues left to these early years. We did find some photographs, however, in a family album. They show Kozin at the centre of a jazz line-up headed by Leonid and Boris Zhukov in the 1920s. The photos give us a glimpse of the exciting musical world that flourished before the ascent of Stalin. Society was more relaxed than it would soon become and Kozin, it seems, lived openly and legally as a homosexual man - something that remained possible until male homosexuality became a crime in 1934.

Media playback is unsupported on your device Media caption Music and words of Vadim Kozin

With his light, intimate singing style, Kozin was so sought-after by the mid-1930s that mounted policemen held back the crowds from the concert halls. The new Soviet recording companies spotted him as a rising star. The labels on these early shellac discs show Kozin singing with some of the most original musicians of the time - like Boris Krupeshev and his Hawaiian slide-guitar orchestra. In 1937, Kozin took a chance and headed for the capital, Moscow.

He was an instant success.

"My grandmother went to hear Kozin in 1938, she was lucky to get tickets," recalls record collector Mikhail Kunitzen. "He sang at the Metropol hotel - a very stylish venue. Afterwards they drank coffee together and Kozin sent grandmother some records as a gift. I still have them."

Mikhail digs among his hundreds of shellac discs, and winds his gramophone to play us Kozin's playful love song, Masha, still warm and bright 75 years later.

When Nazi Germany invaded the Soviet Union in 1941, popular singers got behind the war effort. They travelled vast distances to starving cities and went right to the battle front. Kozin sang the much-loved classic, The Blue Scarf, and composed a cycle of songs about Leningrad, where two-and-a-half million people were trapped under a bitter siege from 1941. His mother and sisters were still in the city.

Kozin was now so famous that, like the celebrated singer Alexander Vertinsky, he moved into the Metropol hotel to live. He was probably staying at this glamorous address when he heard that his mother and little sister had starved to death in Leningrad.

"Last night I saw my sick mother in my dreams," Kozin would write later. "I feel so sorry for her. A life of suffering, a horrible death. I will never forgive myself that I didn't get them out. Forgive me, my dear mother… Nadia and my little dog Mosechka."

Again and again he would return to their deaths in the few pages of the diary that survive.

The secret police, the NKVD, came for Kozin just months before the end of the war. "Anybody could be arrested for anything at that time," says Sergei Lukashevsky, director of the Sakharov Centre in Moscow.

"You could be a minister or a farmer, anybody at all. The court took about 15 minutes to convict you. There was no hearing or proper records."

It is impossible to know how many men were arrested for homosexuality at this time. The records that do remain are open only to a former convict's descendants, meaning that the files on an unmarried person often remain closed.

Find out more

Listen to Marc Almond on the trail of Vadim Kozin, on the BBC World Service, on 27 December. You can check transmission times or listen online here.

It seems likely that Kozin was charged with homosexuality and anti-Soviet activity, and sentenced to eight years in the prison city of Magadan, in eastern Siberia, part of an immense region called Kolyma, most of which lies inside the Arctic Circle. Kozin's records were pulled. His photographs disappeared from the shops, his voice from the radio. He simply ceased to exist as a public person.

"Grandmother thought he was dead," recalls Mikhail Kunitzen. "Everyone thought so. He just vanished."

At this point in our search for traces of Kozin, Marc and I had a stroke of luck - an old friend of Kozin's, Boris Savchenko, agreed to meet us. Savchenko is from Siberia and he first met Kozin there in the 1960s. It is Boris who owns the surviving volumes of Kozin's diary.

"He arrived on the steamer in 1945," said Boris. "They'd march the prisoners off, five by five, with guard dogs standing by."

But when Kozin arrived, Alexandra Gridasova, the wife of the general in charge of Kolyma, was there to meet him.

"She drove Kozin off in her car, and put him in his own cabin and that saved him," says Savchenko.

As Stalin's labour camps were supposed to reform prisoners, camp commanders were encouraged to stage improving musical shows and plays. Rival camp leaders would even compete for the best entertainers. But Alexandra Gridasova had better connections than any of them, and gathered a constellation of stars to entertain the upper ranks of the camp administration.

Purges of musicians after the war, when jazz and other light music fell out of favour, meant that many pre-eminent popular musicians ended up in the Magadan theatre, including the celebrated trumpet player Adi Rosner, sometimes referred to as the "white Louis Armstrong".

Kozin's sentence expired in about 1953, the year of Stalin's death. He was forbidden to live again in European Russia, like thousands of ex-convicts, and moved instead into his own one-room apartment in Magadan. He stayed with the theatre troupe, touring immense distances from the Arctic, to the edges of China to the Volga. He sang his greatest hits from the old days for prisoners and guards, herdsmen and miners in railway towns, in factories, and camps.

Kozin was free, but not free.

The surviving volumes of his diary document his hundreds of concerts in 1955 and 1956.

14 July 1955

They say sing. Sing where we tell you to sing. You can sing here, but not there. To which I say - go and [get lost]... Rulers come and go. I will not grovel in front of them and belittle myself. I am not guilty of anything.

Kozin's diary is a rare guidebook to the Soviet hinterland in the 1950s. It is filled with trenchant criticism of the political system.

12 September 1955

Kemerovo. What a desolate place. Water is in short supply though the river Tom runs nearby. There are shortages of bread! Butter appears very rarely. Big queues form whenever basic foods appear. It's the same in many Siberian cities…There's no doubt that the Soviet Union produces enough food, but the people are not getting it.

When the secret police - by now called the KGB - found and read the diary, Kozin was re-arrested.

Image caption Kozin's 1956 diary

Image caption On 8 October 1956 Kozin lists BBC radio broadcasts from London, and summarises a report from Belgrade

"It was this second arrest that was the point of no return, I think," said Boris Savchenko. "Before that, he believed he might one day return to Moscow or Leningrad - but then he just stopped. He said, Magadan is where I live now and where I'll die."

Kozin remained hidden in Siberia, through the Cold War, through the Brezhnev era. When the Soviet army rolled into Afghanistan in 1979 he was still there.

Then, as the Soviet Union began to heave and split in the 1980s, Kozin suddenly became visible again. Celebrities beat a path to Magadan to meet him, sing with him and have their photograph taken with the frail little old pensioner, a scrawny figure in huge boots and an old sweater stuck with safety pins. He had become the last man standing among a generation of persecuted musicians.

In 1993, the Magadan authorities prepared a magnificent 90th birthday party for Kozin, a grand six-hour concert at the theatre, complete with celebrities flown in from Moscow and St Petersburg on specially chartered aeroplanes.

Choirs sang and officials prepared to present birthday gifts to a throne set up on stage.

Kozin had sung on thousands of stages in every corner of the country, under every Soviet government for three generations. He'd sung as rising star, celebrity, prisoner, and pensioner. But this time he decided not to come. He preferred to stay at home, having a little drink with friends, uncompromising to the end.

In the same year, Russia decriminalised homosexuality. Kozin died not long afterwards, at the end of 1994. Born before the Soviet Union, he had witnessed its every permutation and finally outlived it.

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