Mambo Sun is the first track on the first side of the first proper T. Rex album Electric Warrior, released in 1971.

When I was 13 my favourite group was T. Rex. I bought all their singles, so in the summer of 1971 I was excited to hear they were putting out an album.

I already had their first three singles – Ride A White Swan, Hot Love and Get It On – but this was the first LP I’d heard about, and shot straight to No.1 in the charts to confirm T. Rex as Britain’s biggest band, and Bolan as (in the Rolling Stone review) “the heaviest rocker under 5′ 4″ in the world today.”

I seem to have missed out completely on their eponymous debut as T. Rex, though that was essentially a Tyrannosaurus Rex album retitled to cash in on their new iteration after Ride A White Swan reached No.2 in the singles chart.

They didn’t really make the move away from fantastical fairytale stuff about wizards and unicorns until that March when T. Rex appeared on Top of the Pops to perform Hot Love with Marc in a silver satin suit with glitter under his eyes – the widely acknowledged starting point for Glam.

In those days, if you were nowhere near a record shop – I lived in Germany and went to boarding school in a remote part of North Yorkshire – you sent off for records by mailorder through addresses in the back of the music papers.

I remember the thrill of opening the package to find the matte black LP cover with the bold “T. Rex” logo and a silhouette of Marc Bolan playing his guitar in front of a giant amp. The name of the album was nowhere to be seen.

It didn’t need to be: that image (by Hipgnosis) said it all, with Bolan “electrified” in airbrushed metallic gold paint.

Mambo Sun was the first track I played because it is the first track on Side 1, and I played the whole album to death, especially the two hit singles, Get It On and the soon-to-be-released Jeepster.

And I have only just discovered that Rick Wakeman of Yes plays the piano on Get It On (just as he does on Bowie’s Life On Mars?).