One day in October 1966 I came home from school and found a large man stripped to the waist, attacking the family piano with a woodman’s axe. Seeing the anxious look on my face, my father assured me there was nothing to be afraid of. The axe-wielding man was, he explained, an ‘artist’ who was ‘creating a work of art’.

My 11-year-old brain was puzzled: how could this axe-wielding lunatic be an artist? Can you destroy a piano and call it art? These same basic questions came to my mind last week when I went to Tate Britain and found that very piano hanging on a wall after 11 years in the Tate’s storage rooms.

The piece – entitled, ‘Duncan Terrace Piano Destruction Concert’ – was by the American destruction artist Raphael Montanez Ortiz. Duncan Terrace was the street where my family lived in Islington, north London. So what was Ortiz doing in our house destroying our piano? And, as many will no doubt wonder, what was that piano doing in Tate Britain?

Ortiz had been invited to participate in a Destruction in Art Symposium (DIAS) held in London in September 1966. Poets, scientists, writers, thinkers and artists from America and Europe – including the notorious Otto Muehl and the then unknown Yoko Ono – were invited to explore how the creative community could respond to the violence of modern life. This, after all, was the era of Vietnam and fears about nuclear war.

I’m not sure how Ortiz ended up in our house – most of the DIAS events were held in the Africa Centre in Covent Garden – but I suspect that he’d been invited to pop around with his axe by my father Jay Landesman, who collected avant-garde art and avant-garde people.

Destruction art was all the rage in the early 1960s. Books were being burned (John Latham), clothes were being destroyed (Yoko Ono) and paintings were self-destructing (Gustav Metzger). What was being created in our house by Ortiz was already moving from the marginal world of the avant-garde to mass culture via rock music. Bands such as the Who and Jimi Hendrix destroyed their guitars and equipment live on stage.

Before attacking our piano, Ortiz had already destroyed other pianos – one for the BBC, which turned out to be the wrong piano! And before that, he had been to our house and destroyed a mattress and a comfy chair. At the time I’d wondered what was next: the kitchen table? The front door? Me?

By the way, the Tate also has the destroyed chair – entitled ‘Duncan Terrace Chair Destruction’ – in its collection, but the work is not currently on display. After Ortiz had taken his axe to the mattress, it resembled a giant vulva, what with its internal stuffing on display like pubic hair. What happened to the destroyed mattress is a mystery, but it was last on display in the office of Victor Lownes, then the boss of the London Playboy club.

I remember that day of destruction well. Ortiz gave his ‘concert’ to a small invited audience assembled in the basement, including two curators from the Tate Gallery (as Tate Britain was then known), a sound recordist and someone from the BBC. They watched with earnest attentiveness as the axe thundered into the piano and bits of shattered wood and black and white keys shot across the room. It was a cacophonous assault on the human ear – and the history of art.

When it comes to modern art they say that one man’s trash is another man’s art. Ortiz’s art was all set to end up in the trash can, for after my parents’ death I could find no collectors interested in it.

I was about to put the piano and chair into a skip when a man named Adrian Dannatt decided to pop by the family home for tea. Dannatt is an arts writer and art collector who is a cross between Kenneth Clark and Arthur Daley. When I told him I was planning to dump Ortiz’s piano and chair in a skip, he looked aghast: ‘Don’t do that – let me sell it to the Tate instead.’

‘Don’t be ridiculous,’ I replied. ‘Nobody is going to buy that!’ The piano had, over the years, fallen on hard times. It had lost its status as a work of subversive art and was littered with beer cans, ashtrays, candles and one black bra. We gave it a tidy up before curators for the Tate came to take a look.

Just how unlikely a sale to the Tate would be can be seen by their other purchases of that year – 2012 – which included a portrait of John Ruskin by John Everett Millais, a sculpture by Dame Barbara Hepworth, a sketch by Raphael and a horse painting by George Stubbs.

To my amazement, Dannatt made the sale for a considerable sum, under an arrangement known as the acceptance-in-lieu scheme. It’s essentially a tax-avoidance scheme for the cultural elite; you make an art donation and get a break on your inheritance tax.

So why did they do it? Because, I suspect, the piano and chair are the only known surviving works from that DIAS event of 1966. The Tate saved two artistic works of destruction from destruction.

What’s interesting is its slight rewriting of art history to suit contemporary trends. On the explanatory sign by the piano the viewer is told that for Ortiz ‘the instrument was a symbol of Eurocentric oppression’ and that its destruction was a ‘ritual of release’. That’s not how Ortiz framed it in 1966. He was much more concerned with aesthetics than with politics.

Seeing the piano on the wall at Tate Britain was strange – like running into a bit of your private past in a very public space. I watched the reactions of a group of school kids looking at Ortiz’s creation. Some sniggered with incredulity while others were clearly intrigued. One asked the same question as my 11-year-old self all those years ago: is this art? I think he got a good answer when one of his classmates said that it was and went on to explain why: ‘Because I’ve never seen a piano hanging on a wall before!’