Music is the food of love", according to William Shakespeare. It's also money in the bank for restaurant owners. A recent study conducted in central England showed that classical music has the power to persuade people to part with their cash.
The sounds of Mozart, Bach and Beethoven make diners feel more affluent and encourages them to spend more... significantly more. During the three-week study, average checks varied depending on the type of music played in the restaurant. Classical music resulted an average expenditure of $40 per customer, whereas $35 was the going rate per customer listening to Britney Spears.
According to research done by Charles S. Areni and David Kim from Texas Tech University, the term atmospherics is used "to describe the various visual (color, brightness, size, shape), aural (volume, pitch), olfactory (scent, freshness), and tactile (softness, smoothness, temperature) dimensions of a store that can influence the purchase probabilities of consumers." Areni and Kim's research focused on wine purchasing. The short version: classical music and wine purchasing go hand in hand. It wasn't that consumers bought more wine. In this case, they bought more expensive wine.
Some consider this blatant (and unethical) consumer manipulation. But it's a common marketing and merchandising practice across all industries, and I think it's just common sense. At the very least, you'll want to carefully consider the affects your sound effects have on your customers.
On one hand, to avoid offending the ears of your guests, your music, whether easy listening, top 40, or classical, needs to "fit" with the style of your restaurant and the age of your customer. When the fit isn't right — when we're subjected to unpleasant atmospherics — the wait seems longer, the service seems poorer, and the price/value relationship seems lower. Not a great impression.
To produce positive results, you'll need to carefully consider the finer aspects of music in your restaurant. While volume and tempo are important, generally it's the genre of music that matters most.
So, there's no wrong or right music per se, but there is wrong and right music for your restaurant. For those interested in reading more on the subject, download a list of selected articles.