If the image of a man in a gondola whipping an ice cream cone out of the grasp of a pretty girl in a passing boat makes music burst unbidden into your head, you are perfectly normal.
A survey of the top 10 catchiest advertising jingles ever, by the makers of Chicken Tonight sauces, has just put the long-running 1980s Cornetto ad on top, chased by Go Compare!, P-p-pick up a Penguin, and A Mars a Day. Six of the 10 are confectionery or convenience foods, two cleaning products. Go Figure! Bored house-persons doing the shake 'n' vac, stuffing themselves with sweets while watching insurance ads on telly.
But, why does the Cornetto tune get stuck in our brain even more than the others? If, in 1898, the Neapolitan composer Eduardo di Capua had known how much money Unilever would make from his song "O Sole Mio", once it had embellished it with a catchy ditty, not to mention how many people would be unable to get the song out of their heads, he would have gone into the ice cream business. But that's hindsight for you; and in fact the trick of lining a cone with chocolate to stop it going soggy was only perfected in 1959.
Is the secret simply to recycle a melody we already know and love? Does familiarity breed contentment? Look no further than the current Uefa Champions League opening theme to hear a version of Ukrainian composer Sergei Prokofiev's Peter and the Wolf played over giant animated puppets of famous players, including Ruud Gullit, looking like a cross between Talus the Guardian of Crete in Ray Harryhausen's 1963 film Jason and the Argonauts and a Comfort conditioner puppet.
Uefa has had its hands in the catchy classics till before – in 1992 it commissioned an arrangement of Handel's Zadok the Priest for its official anthem. One can easily make the intellectual link from musical greats to football greats. Or listen to rugby championship supporters roaring "I Vow to Thee my Country", the muscularity of the song reflected in the relish of their voices and the thighs on the field, and you see how unconscious forces are at play; and how well-chosen musical memories, evocations, stimulations and motifs unite or persuade; or could even, in the case of Nazi rallies, coerce.
It is also true that where musical sound modulates into noise, repetition can spill into aggression: an example is "white noise" torture in, say, The Ipcress File, the 1965 film starring Michael Caine, scored by John Barry, one of the greatest composers of unforgettable melodies, including the James Bond theme.
As early as 1876, Mark Twain understood and captured the compulsive, catchy power of jingles, and also used the word. In his short story A Literary Nightmare, he, as narrator, hears a jingle so compelling that it takes possession of him, makes him haggard and unable to function, until he passes it on to someone else; in a sense infects them with it.
This involuntary conjuring of music has a Pygmalian quality, in that a shapely creation of the brain takes on a life of its own, beyond the control of the instigator.
With the advance of scientific knowledge 80 years later, Arthur C Clark sharpened the theme in his story, The Ultimate Melody, about a tune so keyed to the electrical impulses of the brain of its inventor Gilbert Lister that, enmeshed by it, he becomes catatonic. Not something one expects to happen even after a great many lusty choruses of "Everyone's a Fruit and Nut Case".
In a world increasingly bombarded by relentless sounds and images over which we have no control, from ads to apps, the infectiousness of certain tunes, that Oliver Sacks called sticky music, is getting a lot of attention, along with their ability to worm their way into our brains, lodge there, and pop out again without warning. And this is not just because of their obvious financial importance in helping flog unwanted things to the unsuspecting.
To mark their new fame these irritating little sonic jiggers have a name – earworms – a term so self-explanatory that it has burrowed into our neologistic pantheon and made itself a cup of tea.
Earworms are the topic of a serious psychological survey by Goldsmiths College, London, run by Vicky Williamson, a lecturer in music psychology. The Earwormery study, involving more than 7,000 people, is looking at the cognitive phenomenon known as involuntary memory – or mind-popping – in the hope of learning more about memory processes.
In the case of earworms, a 2006 Finnish survey of 24,000 people found that 91 per cent of us regularly go about our days with songs like "I See you Baby, Shakin' that Ass" (Renault Megane) playing in our heads, along with an image of pneumatic bottoms, which certainly says something.
A surprising finding is that tunes are most memorable when easy to mimic, perhaps a hangover from the learning technique of babies, who mimic sounds as they begin to build language, says Williamson
"Sonic ident" composer Nick Norton-Smith explains that what gives an earworm burrowing muscle is simplicity, linked to memorable imagery. "The more irksome, the more facile it is, the harder it is to get it out of your brain, like the Marmite theme, that can annoy the hell out of you, but it sticks," or the Flake ad, with "a girl eating a flake in a mildly suggestive way". There are big rewards for a successful cross-platform, multi-territory ident, which could, for the very best, be as much as £50,000-£100,000, yet could take just 20 minutes to write.
Tim Garratt, the composer for the new upcoming Johnny Twoshoes iPhone game, Prevail, broadly identifies the same two things, familiarity and simplicity. Take the four-note Intel Inside jingle (all flats: D, G, D, A). Garrat explains how it lets you say the syllables of the product in time to the music. Clever. Meanwhile, what we might see as the parasitic or symbiotic re-use of an existing melody, can lead to songs such as "O Sole Mio" entering the popular consciousness, which Garratt calls "the holy grail for advertisers".
In the past, musicians didn't want to be associated with adverts, and earned enough money not to need to. But, as a successful composer who prefers not to be named, explains, that has all changed. In a culture of free-plays and sharing, young bands need to get their music into the public domain to boost familiarity and sales, and adverts are ideal for this. He says the main thing that makes a tune "sticky" is simply repetition, but offers a caveat: "Repetition can make you remember it, but it can't make you like it." And Irving Berlin (whose film scores include Top Hat and White Christmas), perhaps uniquely, refused to allow any of his songs to be used for advertising ever.
Are earworms snatches of melody that burrow their way into your mind and won't come out, or are they just more aural flotsam that gets wedged in there, like earwax and idle gossip? As a cautionary tale one should try to remember the song by German Capella group, Wise Guys, titled "Ohrwurm" (Earworm) whose lyric, "Hello! Hello! I'm your Earworm," is so instantly forgettable that our recent Eurovision contribution sounds enticing by comparison.
So, let's not give them too much cochlea-room for, according to one survey, 7 per cent of us have a jingle in our heads when having sex. Though hopefully not Go Compare!
Take part at www.earwormery.com