HE was a real showman, was Alex Harvey. He was the charismatic singer with the Sensational Alex Harvey Band - a restless presence at the front of the stage, clad in a black-and-white striped T-shirt.

Even four decades on, fans remember SDAHB's Christmas shows, when, during one song, several female dancers suddenly turned around to reveal backless dresses and a striking absence of underwear.

The song, naturally, was called Cheek to Cheek. The place went crazy, Harvey's friend Billy Connolly would say, many years later: "He was a great entertainer."

Harvey died in February 1982, the day before his 47th birthday. Now, 34 years later, he is getting the anthology treatment - a deluxe, 14-disc, 217-track box set containing his early solo albums, the eight SAHB LPs, selected tracks from his post-SAHB career, plus live sessions, home recordings and a 64-page hardcover book with rare photographs from the Harvey family album, all in a heavy-duty slipcase.

It's called The Last of the Teenage Idols, it's called.

Harvey was born in the Gorbals in February 1935. He left school at 15 and had a succession of jobs but he had already fallen for rock 'n' roll, joining groups such as the Clyde River Jazz Band and the Kansas City Skiffle Group.

In 1957 he won a newspaper competition to find Scotland's answer to Tommy Steele. A sequence of bands ensued, culminating in the Alex Harvey Soul Band. They released an album in 1964 and Harvey went on to have various projects over the next few years. In 1968 he began a four-year stint as rhythm guitarist in the orchestra in the hugely popular musical Hair.

In 1972 he was introduced to Tear Gas, a heavy-rock Glasgow outfit. They gelled, and SAHB was born. They released eight albums in the six years to 1978 and became famous for their extraordinary live shows.

Few knew Alex better than Trudy, his second wife. They first met in 1965, when the Soul Band had a residency at London's celebrated Marquee venue.

"I must have been about 17 or 18," Trudy says. "I went to see Long John Baldry. The Soul Band were the support group. I went with someone who knew Alex vaguely, and she introduced me to him. But prior to that, when I saw the performance, I thought he was an amazing performer. He put me in mind of a kind of highwayman. He was so charismatic.

"The band were very Glaswegian ... It was all 'get that ------- gear on the ------- stand, for ----- sake', that kind of language. I come from Leigh-on-Sea in Essex, and it sounds so crazy now, but I had hardly heard that word before. But I remember watching them and thinking, 'This is interesting.' The Soul Band were brilliant: I loved that kind of music."

In time the couple married, and they moved into a flat in Redington Road, in Hampstead, north London. In 1967 young people were basking in the summer of love, a great time for hippies and flower power. "We lived in a house with seven musicians so there were a lot of comings and goings," remembers Trudy.

One acquaintance was David Bowie. "We knew him around the time he was working with the mime artist Lindsay Kemp. He stayed with us for a while, and then just on and off. Alex and David would talk about science fiction, and I think Alex introduced him to Arthur C Clarke's books."

In 1976 Harvey launched his own project, Alex Harvey Presents the Loch Ness Monster. In the sleevenotes he spoke of his belief that the loch contained a "colony of creatures as yet unnamed by modern science". He donated the profits to wildlife preservation. He was ahead of his time in that respect.

"Absolutely," says Trudy. "He always told people, 'Don't ---- in the water supply.' In his lyrics and his music he was very much about, 'What are we doing to the planet?' He read a great deal. He loved his home, his children, his animals. He was very much someone for the home. He put up shelves, he did his handyman stuff. He was just, to be honest, an ordinary guy. He was interested in history and politics – he came from a political family. In his lyrics you can tell what he believed in.

"He also collected little Victorian lead soldiers – he used to go to Camden market and buy broken ones and at home he would fix them, give them new heads and repaint them. He was fascinated with the British Empire and the military. Some people assume he wanted to be in the army, but quite the contrary.

"Someone asked me the other day if Alex was ever violent. Did he get into fights?" She laughs. "I never knew him get into a fight. Don't forget, Alex was an actor. He got on the stage, and if he was playing a gang member, whatever it was, he would play the part. He did Delilah tongue-in-cheek, for example. He could sing those songs, and everybody understood it was a joke."

Harvey quit SAHB in 1977, worn out by touring and by having to cope with a serious back injury. He went on to assemble new musical projects; sadly, however, he didn't live to see the release of his final album, The Soldier on the Wall. On February 4, 1982, he suffered a heart attack while returning home from a gig in Belgium. The 64-page book in the box set quotes Charles Shaar Murray's NME obituary, in which he cites Harvey's warmth, humour and compassion. Is that what Trudy most remembers? "Absolutely. He had a great sense of humour. He would get one of his golden retrievers and he would sit it on the table next to him and tell people, 'This is the most intelligent dog in the world – ask him a question.' People would ask a question and after a pause Alex would say, 'No – that's not intelligent enough. He won't bother with that.'"

The hope now is that the box set will not only be treasured by fans but will also attract lots of new, younger admirers.

Harvey, says Trudy, "even though he was a pacifist, he had a kind of warrior aura about him. It was a kind of attitude of 'don't give up'. He had a definite message: not to fire any bullets, to put it in a nutshell, but also that the kids should not be destructive. He identified very much with the younger generation, and he felt that things would change ... But if you were to ask what was it that defined Alex, I think it was that he dared to be close to the edge. And I think this box set is a wonderful celebration of one of the most creative and innovative people of his time."

* The Last of the Teenage Idols is released by Universal next Friday, priced £110. Visit sahbofficial.co.uk