Think you know David Essex, have him pinned down as a ’70s Robbie Williams, all self-deprecating cheeky chappie grin? Well, think again. On the evidence of the six albums he made for Edsel from 1973-77, Essex’s music really was fucking weird.

Take, for instance, his 1973 breakthrough smash “Rock On”. Rarely has such a nostalgic record sounded so futuristic and yet somehow lost (“Which is the way that’s clear?”). And credit is overdue to Essex’s visionary producer Jeff Wayne who, with his dub spaces and raised-eyebrow strings, is the missing link between Norman Whitfield and Lee Perry.

Rock On, the album, similarly journeyed to some very strange places. Laden throughout with backwards drums, absurd vocal phasing and guitar barrages, a song like “We All Insane” could pass as an outtake from Eno’s Here Come The Warm Jets. And Massive Attack fans may be startled to discover the origin of their “I was looking back to see if you were looking back at me” refrain on the extraordinary “Streetfight”.

The self-titled 1974 follow-up was even more bizarre. True, there was the cheerful satire of “Gonna Make You A Star”, but there was also “Stardust”, far more suicidal than Ziggy… with its drowning gongs, and the mind-bending proto-industrial “Windows” which almost outdoes Nine Inch Nails in its brutality, culminating in a cacophony of police sirens and a child’s voice screaming “Mummy!”

All The Fun Of The Fair (1975) has Essex grinning maniacally on the cover, as if he’s about to slit your throat, and the moment where the all-out freeform pile-up which climaxes the title track (“Let’s take a rrrrrrIDE!”) segues into the jolly granny-favourite “Hold Me Close” remains one of the most startling in pop.

But Out On The Street (1976) is his masterpiece; 47 minutes of nervous breakdown set to music-almost the Sister Lovers of glam-from the slow death of the 10-minute title track (“PIMPS and PONCES!”) through to the excoriating seven-minute death disco of “City Lights” (with a bass line which, shall we say, anticipates “Guns Of Brixton”), Essex sounds hoarse and near-psychotic throughout. This is the album Robbie Williams is yet to make.

After that, Essex tried his hand at self-production with 1977’s back-to-basics Gold And Ivory. Although musically far more conservative, the element of doubt is still present in songs like “Good Morning (Darling)”?perhaps the most affecting song Essex ever wrote-and the remarkable “Britannia”, in its own way as punk as anything else in 1977 (“Complacency shat in your eye”).

Think you know David Essex? Listen to this astonishing body of work-he belongs in the company of Peter Hammill and Kevin Coyne.