In the 1980s, if you liked a song you went out and bought the single on 7-inch vinyl. If you loved it you went out and bought the 12-inch version instead.
This was an exciting innovation in popular music - putting a single on album sized vinyl was heralded as a great breakthrough by the music business.
The larger disc reproduced the audio better - so we were told - due to the extra groove space. Not that your average punter could tell the difference.
Of course, slapping the same song on a larger disc and charging more money for it was never going to fool anyone, so the record companies came up with a plan - the 12-inch remix.
The theory was simple. If you liked a song a whole lot, you would want to hear more of it. So they took the track and added to it, making it longer to fill up space.
These extended versions were generally referred to as 'dance' remixes - on account of the fact that they sure as hell weren't 'listening' remixes.
12-inch remixes typically went on forever. You could put a track on, listen to it for five minutes, check the label to make sure it was actually the song you thought you'd bought, go into town with your mates, shoplift some pick 'n' mix from Woolies, buy Smash Hits, 15 cans of hairspray and a Rubik's Cube, go home, read your mag, style your hair, solve the puzzle and return to your bedroom just in time to catch the bit of the song you actually recognised and liked - the 7-inch section.
When that bit finished you could go out again, safe in the knowledge that you still had hours to go until the finale - five electronic handclaps and a fade-out.
After ten years of remixes the CD arrived, and the 12-inch single became a thing of the past.