Isn't that what they're calling it these days?
In years gone by it was a medley, then it was a mexa-mix and now it's a mash-up - but call it what you will: there's nothing worse.
Clearly: this is an exaggeration. Murder, War, Famine, Jazz - these are all heinous Things That Must Be Stopped, but when it comes to music it doesn't get much worse (once you've ruled out the aforementioned J word)
There you are happily listening to a bit of Elvis and some DJ, out to prove him/herself, comes along and scratches that ole vinyl (or however you get that sound now that vinyl has gone the way of the Dinosaur) - and all of a sudden a whole generation of children grow up thinking that The King had a stutter.
And then just when you are singing along it jumps into some other piece of song, which you get a snippet of and then it's off either into a third or back to the first.
Many bands who have been around for a long time use Medleys as a way of covering their extensive back-catalogue: because let's face it even Genesis fans, accustomed as they are to interminable drum solos, can only take so much and once you've got through the whole of "Supper's Ready" (which goes on for 23 minutes) it doesn't leave room for much else in a 2 hour set.
But if I ever came to power then high up on my initial list of commandments to the world would be the banning of all medley's, mega-mixes and a severe frowning upon would be issued to mash-ups on the grounds that only people desperately trying to fool themselves that they are still "down with da kids" would ever use such a term.
Because, and let's face it, if a song is worth playing in the first place - then it's worth playing all the way through, right? And if it isn't - then why bother playing it in the first place?
Or is it just the case that in our bite-sized information worlds our attention spans are simply no longer sufficient to cope with doing one thing for any length of time?
(Confession time here guys: I don't like medleys - but I do quite like a bit of Genesis. Sorry)