Dad was still alive when I started the novel version of Don't Turn on the Light. He read the first few chapters sitting on my sofa, about a month before he died.

So much has happened in between. The river of life flows on.

The other night I was listening to a song called 1971. The lyrics got me thinking about that year. What could I recall of that time? I remembered I'd been to a Pink Floyd concert - with Dad. I wasn't allowed on my own - mum worried about me becoming exposed to drugs and sex. I was sixteen. Although I don't suppose much has changed, it seemed things were different in those days.

I decided to record the gig on a BASF 240 minute cassette, or was it a 180? It's difficult to recall that detail now, but anyway, I taped the show, and in the following years, my brothers and I wore the thing out. The songs, the voices in the crowd, I came to know by heart. Eventually, it broke, got tangled up around the rollers of the player. I would never have thrown it, but someone in the household did. That was getting on for fifty years back. I can't tell you how many times since I've lamented the loss of that tape.

The following day, I got up and checked YouTube for any footage of that particular show. There wasn't any - apart from a couple of audience recordings of inferior quality, just as mine had been. Then I spotted one labelled Good Quality - The Return of the Son of Nothing, the original title of Floy's album Echoes. I selected the play button. Roger Waters announced the name of the song, and I heard a familiar voice say. 'Do you know that one?' Moments later, another, perhaps even more familiar. 'No, I've never heard it.'

My father and I! 

Forty-five years later, his familiar tones had reached out from a place in time to reunite me with those memories, on a long-lost copy of my own recording, which I'd discovered while writing a story about time and space.

Even now, I'm still reeling from the coincidence.