Caroline is so simple a song that you might think it could have been written on a paper napkin. And it was.

Francis Rossi and the band’s roadie-cum-harmonica player Bob Young came up with it in a hotel in Perranporth, Cornwall, when the two families were on holiday there in 1971.

I don’t know the details but I’m picturing a scene in the bar, after dinner, once the ladies had gone up to bed and the boys stuck around for just one more drink. And they really did scrawl it on a table napkin.

I don’t suppose it took that long.

Caroline began life as a slow blues, and a demo was recorded that way with Rossi playing guitar and bass, and Welsh drummer Terry Williams of Dave Edmunds’ Rockpile, plus some barrelhouse piano.

The band later doubled the tempo and recorded it mostly live, using their stage gear and amplifiers. It’s got the archetypal Quo souond: chugging along like a freight train, the heavy load anchored by John Coghlan and Alan Lancaster on the drums and bass while Francis Rossi and Rick Parfitt riff away on their duelling guitars.

You can almost hear an imaginary whistle blow to signal the grinding gear-shift when Rossi drops out and Parfitt plays the melody on his own for a bit before Rossi comes crashing back in again for the finale.

It always seemed unfair to me that Status Quo, dependably the same in style and sound, reliably and relentlessly doing exactly what it said on the 12-bar tin, never really received much musical credibility.

Especially when compared to groups of whom the same could be said – for example, The Ramones, or even Metallica, who did the same thing on different tins. I imagine it seemed even more unfair to them.

Never mind, I’m sure they’d be happy to show you the money they’ve made from having more hit singles than any other bnd in history.