It is music. Or rather, it is Muzak, for there is a difference. As well as being a generic term, it is also a large and thriving company based in Seattle, in the fashionable Pacific North-West of the United States, with revenues of about $100m. It pumps out its product via satellite feeds to thousands of businesses across America, broadcasting 60 different programmes, of which only one is now classic "background music".
It has its origins way back in the 1920s, when a military officer was trying his hand at the new science of telephony. General George Squiers was a formidable character, who experimented with radio in 1897, only a year after Marconi sent the first wireless message, and was the first passenger in an aircraft when he flew with the Wright brothers. He helped to create two of the most powerful instruments of American global domination: the United States Air Force, and Muzak.
General Squiers formed the name of his company from "music" and the name of his favourite high-technology company, Kodak. It was a roaring success, quickly becoming the soundtrack to the American century.
Whispering strings played cover versions of the Carpenters' "Afternoon Delight" or "A Walk in the Black Forest" as Americans went to the supermarket, the garage, motels, restaurants, fast-food joints or the toilet. It even accompanied Neil Armstrong to the Moon. When the US left Vietnam in 1975, the helicopters clattering away through small arms fire, Muzak played heedlessly on in the lobby of the American embassy while puzzled North Vietnamese soldiers skidded about the marble floor.
Much of it was, by common consent, terrible; unimaginative, dreary, saccharine- sweet rubbish that grated on the nerves. If that is still your mental image of Muzak, however, it is perhaps time to think again. Two years ago, the company had a small revolution, and it has put the emphasis back on the main product.
"This company was built on believing in the power of music," says Kenny Kahn, the vice-president for marketing, and music is now what it is about. Most of the programmes offered by Muzak these days are what they call "foreground music" - original versions of the songs, not camped-up reproductions. And it is more likely to be Nirvana or Jimi Hendrix, great products of the city of Seattle, than "Puff the Magic Dragon" arranged for strings.
The company no longer wishes to think about the bad old days and has become (slightly self-consciously) hip.
"Our goal is to say to people, `We are not what you think we are'," says Mr Kahn.
It has a whizzo website and lots of new concepts to describe what it does, which sound like the sleeve notes from a techno album. Its technicians are now described as "audio architects". And it has paid off: last week, the company was bought out for more than $250m (pounds 150m) by a Boston-based firm. It will take a long time before the word loses its associations, but at least people have heard of it.
"We have to deal with that," says Mr Kahn. "It's better to be recognised in some shape or another than not to be recognised at all," he says, paraphrasing Oscar Wilde.
Muzak is the the world's largest radio station, sending DJ-free music around the nation by satellite and wire. It is about to start using the Web to sell its wares, taking a logical step on from its earlier use of technology: after all, General Squiers' company was originally called "Wired Radio".
And Muzak is no longer a term of pure invective, as it was a decade ago. Background music has become deeply fashionable, with the sound repackaged as "ambient", "lounge" or "cocktail".
It has not been universally popular in the Independent building in Washington. The property company that owns the block told us in its newsletter that everyone loved it, and that feet had been seen tapping in the corridors. Some, however, were banging their heads on the wall. There were dark plots hatched, whisperings about pliers and wiring systems. Suddenly last week, the seventh floor was silent again. But by Monday, it was back: Muzak is, it seems, an unstoppable force.