Okay, how do I explain this one? I think I'm going to blame Sarah Cracknell. Interviewing the Saint Etienne singer last year she said that this David Essex single was one of the first she bought and what had always struck her was how unusual and bizarre it was. Nearly 40 years later "it still sounds strange," she added.
Fast forward 14 months. I'm looking through the choices for 1973. It's a slightly cursory look. I've pretty much decided that the winner is going to be T.Rex's 20th Century Boy because it's one of my favourite pop songs of all time. Still, there's a lot of stuff that I like from that year, more than I imagined. Some of it would be the choice of the ten-year-old boy I was at the time - The Sweet's Ballroom Blitz, which starts at the level of hysteria and somehow keeps rising, and Elton John's Bennie and the Jets (the only Elton John song I can say I truly like) - and some of it I've come to later - the raucousness of Iggy Pop, the trashed glitter of the New York Dolls, the sweetness of Hall & Oates.
But when I notice that 1973 is the year Essex put out Rock On, the ten-year-old boy in me remembers liking it and so I give it a play.
And here's the thing. Sarah Cracknell was right. It still sounds strange. Strange and bizarre and rather eerie. It has this curious dislocated brilliance to it.
One of the dangers in pop is we back-project. We impose our retrospective knowledge on the past. David Essex has long been a victim of that, I guess. His career in musical theatre and soap opera has cast a shadow back over his earlier years. We assume he was always a light entertainer because that's what he became. (He might call it making a living, of course).
Maybe his chance of being taken seriously had long gone by the late seventies anyway. Near the start his obvious good looks made him pin-up material for the likes of Jackie magazine and as a result his early supporters in the music press soon kept their distance.
As a result, though, the adventurousness of his career in the early seventies is a little overlooked (although Massive Attack of all bands seem to have been listening. There's a lyric on Safe From Harm that may have been sampled from Essex's track Streetfight).
Essex came to prominence when he starred in two films - That'll Be The Day and Stardust - in which, if memory serves, he's very good at playing a really rather dislikeable pop star. Both films are interesting, rather disenchanted visions of pop life (hideously so in the latter's case).
And some of his early records have a similar surprise to them, nowhere more so than here. Rock On is a studio single. It's all about mixing desk experimentalism. The mixologist in this case was Jeff Wayne, better known now for his War of the Worlds double album and stage show. (Another retrospective taint perhaps.)
Listen to Rock On and what strikes you is the spacey, minimalist bravery of the thing. It's a thing of echoes, sudden pauses and rumbling racket. A pop sonic infected by the ghost of dub, it's got Herbie Flowers on bass, Alan Hawkshaw on the Moog and keyboards. Then there are these shrill violins that cut through it like a serrated knife.
Essex's voice, meanwhile, bounces around in the mix, echoing around in the emptiness of the sound and then doubling and tripling up on itself towards the end. As Saint Etienne's Bob Stanley has pointed out, this is as avant garde as anything by Bowie or Roxy back then.
The lyrics aren't up to much, I guess, but they speak to a couple of things. There's the early seventies pop nostalgia for the innocence of fifties rock 'n' roll in them ("Still looking for that blue jean baby queen") and a sense of the confusion and uncertainty of that moment, swamped by a post-sixties fug ("Where do we go from here/which is the way that's clear"). It is looking back to a fondly remembered past and forward to an uncertain future.
Is it a record I love? No, but it is one I'm intrigued by. Its originality and novelty deserve to be applauded. And I like novelty. It's one of pop's most entertaining playing cards.
See this then as representative of all those songs that come out of nowhere, from artists who may have done nothing of consequence before or after. See it as representative of pop's capacity to surprise.
In the end pop's principal pleasure is the shock of the new and yet some listeners want the comfort of the familiar. It's to David Essex's credit that he didn't always hold to that notion.
20th Century Boy, T.Rex
If You Want Me to Stay, Sly & the Family Stone
Search & Destroy, Iggy Pop
She's Gone, Hall & Oates
Jet Boy, The New York Dolls
The Jean Genie, David Bowie
I Can't Stand the Rain, Ann Peebles
Living for the City, Stevie Wonder
And the best-selling UK single of 1973: Tie a Yellow Ribbon, Dawn featuring Tony Orlando.