There's a famous line in Noel Coward's play Private Lives. A couple - once lovers - meet by chance on the terrace of a French hotel.
Because they're middle-class English people and this is the 1930s, emotions are repressed.
But off-stage a dance band is playing. The couple are moved, despite themselves.
"Extraordinary," one of them says, "how potent cheap music is."
The line is partly Coward's joke at his own expense: the tune the distant band are playing is one that in real life he wrote himself.
But Coward knew that what one of his characters dismisses as "an insistent little tune" IS potent.
Cheap music - often dismissed as superficial, schlocky or rubbishy music - is popular music.
It has instant ear appeal. It has melodies, preferably well-known and recognisable, and clever orchestrations, contrived to deliver maximum impact.
It's designed to trigger feelings the listener can wallow in, sentimental, elegiac, celebratory or martial. It deploys musical cliches with aplomb. What's not to like?
Joy of cliches
Of course, the cliches alone are enough to ensure that musical snobs dismiss it.
But - as successful purveyors of cheesy music like the late James Last are well aware - there's a reason why cliches are cliches.
People like them. You know where you are with a good cliche.
Whereas true musical originals are on dodgy ground: Beethoven's music often baffled his first listeners; today's contemporary composers of Western art music appeal only to a tiny coterie.
Some cultures seem especially susceptible to this kind of musical kitsch. It's probably no coincidence that James Last was German.
The Germans have a special word for saccharine pop: Schlagermusik, they call it.
Schlagermusik is popular across much of central Europe, especially when it involves tunes you can sing along to in public.
The schlager sensibility has even infected other musical genres.
The Dutch-born violinist and conductor Andre Rieu has made a great success of performing Viennese waltzes and operetta in televised open air concerts with singers in flouncy ball gowns and elegant tailcoats: the best bits are often when his audience joins in, singing and swaying.
In general, whether you think music good or bad is a matter of personal taste and ought to remain so.
Each to their own
You may wince at the notion of a bearded folk singer, hand cupped to his ear, on the umpteenth verse of some lachrymose traditional ballad; personally I'm a fan. I think it has an appealing rawness and authenticity.
I can't say the same about punk rock - which of all popular music genres has the best claim to be truly, deeply, ear-shatteringly awful.
The UK's top 10 catchiest songs
- Spice Girls - Wannabe
- Lou Bega - Mambo No 5
- Survivor - Eye Of The Tiger
- Lady Gaga - Just Dance
- Abba- SOS
- Roy Orbison - Pretty Woman
- Michael Jackson - Beat It
- Whitney Houston - I Will Always Love You
- The Human League - Don't You Want Me
- Aerosmith - I Don't Want To Miss A Thing
Source: Hooked on Music experiment/Mosi
But others thought it a wonderful counterblast to the self-indulgent commercialism of most pop.
They thought, in fact, that it had an appealing rawness and authenticity.
So is cheap music, rubbish music, really bad? Of course not. Some of it - think Abba - is musically highly sophisticated.
It's deftly executed and technically demanding to write and to play.
Its fault, if it has one, is that it makes a direct and naked appeal to the emotions.
And that makes some people uncomfortable, embarrassed.
It transports its listeners from the humdrum every day to a world of heightened feeling, with minimal effort on their part. I'll sing along to that.