When I first heard this song in 1973, I thought it was the strangest and most compelling piece of music I had ever heard. It still thrills.

One can only admire the splendid arrogance of Steve Harley to make his debut single an emotionally overwrought seven-minute epic featuring a 50-piece orchestra and choir, boasting a signature sound of “no guitars” but a prominent violin. And to top it all, it’s about a bloke called Sebastian.

Impossible to categorise, it does not so much tread a thin line between admirable ambition and pompous pretentiousness as flounce across it and throw everything in your face, including the kitchen sink.

In many ways it is everything I cannot abide: long and overblown with baroque embellishments, an orchestral arrangement, a chorale section and an absurdly mannered vocal style that overenunciates every word, with a rhotacism so ridiculously affected that, had this not come out a decade before The Life Of Brian, you’d be tempted to shout “Welease Wodewick.”

Harley was a journalist before he became a pop star. He had trained on the same NCTJ course as me, at Harlow Tech a few years earlier, and spent three years working as a hack before turning his wordsmithery into song lyrics and trying them out on the general public as a busker on the London Underground.

That’s where Sebastian began life. Unsurprisingly, his self-styled “gothic poetry” didn’t make him a penny on the streets of London: it’s not exactly singalong material in the vein of, well, Streets of London. Nor was it a surprise when this most uncommercial of songs failed to crack the charts; that wouldn’t happen until Judy Teen the following year.

Bizarrely, Sebastian was a big hit in Europe, topping the chart in several countries, possibly because they were unable to decipher those lyrics. They were not alone, frankly: Harley has a delightful way with words, and a very particular way of wolling them awound in his mouth – and at other times rrrrrrrolling them arrrrrround – but they don’t always make sense.