Sounds for Spaces

When you go shopping, what pushes you over the edge from "maybe" to "I'm buying that"? Perhaps it's the skill of the salesperson, the product's packaging, the primal hunch that the thing you're coveting will make you feel good. Or maybe it's the beat. The shop's background music you're barely even aware of; that subtle sonic layer permeating the retail environment…

However much you love music - the songs that make you dance, cry or dream-you might never have considered that some tunes can also make you spend. Neither, I'll
bet, did the thousands of shoppers around Europe who were unwitting participants in a recent series of experiments that took place in bars, restaurants, book shops, supermarkets and perfumeries. Across hundreds of such locations, researchers made various changes to background music - and then watched as sales went up.

In supermarkets and book shops in Finland, switching to more well-known music than was previously used there triggered a 12 per cent spike in sales. In Ireland, alterations to playlists used in bars and restaurants were associated with people staying longer - and spending more. And in the Netherlands, slower-paced music in a chain of perfumeries appeared to drive a sales increase among customers who were part of the chain's loyalty programme. "Our experiments," says Jaap Gordijn at VU Amsterdam, a university, "are the tip of the iceberg".

For decades, researchers have known that music can be used as a powerful form of behavioural nudging - the theory that says it is possible to influence what people do through subtle cues or arrangements. One form of nudging has even boosted organ donor numbers through the quiet introduction of 'opt-out' policies, which require people to actively remove themselves from national donation registers.

But music has had a particularly colourful history in the word of nudging. In the early 2000s, some London Tube stations began playing classical music in their foyers. This soothing ambience, seemingly unloved by society's more nefarious characters, reportedly caused a drop in robberies, assaults on staff, and incidents of vandalism. "The trial of classical music was well-received with our customers and staff and, following this, it is now played at some Tube stations across London at the discretion of station staff," says Mark Evers, Transport for London's lead on customer insight, strategy and experience.

The right stuff

The idea that music could also influence purchasing has been around since at least the late 20th Century. One highly cited 1999 study showed how playing French music in the alcohol section of a supermarket boosted purchases of French wine. Conversely, German music increased German wine sales.

Countless such experiments have been conducted in the years since. Including by Gordijn, his colleagues and partners at various research institutions as part of their EU-funded Music360 project. It seeks to find out how valuable - to retailers and hospitality businesses - music really is. The various trials carried out as part of the project took three years and Gordijn says some of the findings reveal that playing commercially licensed music, such as well-known pop tunes, in premises can in some cases boost sales. It suggests that, for retailers, investing in carefully curated playlists and access to a wide range of popular songs may be worth it.

Owning a retail or hospitality business and not using music to try to influence consumer behaviour is "completely bonkers" from a commercial point of view, says Ola Sars, founder and chief executive of Soundtrack, a Sweden-based digital music provider. The company offers a total of 150 millon tracks licensed for commercial use and currently operates in 75 countries.

Sars cites one example from his vast client base: changing the music played in a well-known hamburger chain helped boost sales by 9 per cent. "Mainly, what that came from was people buying more desserts after dinner," he says. Sars and his team experimented with four different options, including playing no music at all. But one approach stood out - using popular, but not super recognisable, music to create a fun, edgy feel: "Indie, I would say, but it was still kind of mainstream pop."

The more recognisable music used in another playlist during the trial didn't perform as well. It might have been, in contrast, distracting, theorises Sars. Customers perhaps began thinking more about the familiar songs they were hearing - rather than going back to the counter for more food, he suggests.

Soundtrack aims to match playlists to brands. Sars even hired a team of musicologists for three years, tasking them with training an algorithm to connect specific music to various "brand values". This was somewhat subjective but involved associating tracks with, say, the concept of 'affluence' - which might be an important attribute for some retailers in terms of how they see themselves and their customers. "We have trained our machines to interpret those brand inputs and to translate that into music," says Sars.

Curated content

Many businesses want to have a "sonic identity", explains Marcus Andrew Webb, who runs Sonic Element, a consultancy in the US. He describes developing soothing instrumental music for a clinic and, when I ask why they wouldn't just grab a royalty- free CD of panpipe melodies, Webb says that some businesses are keen to create a sound-space that is unique to them.

Perhaps it's also just as much about quality control. Somewhat amusingly, a 2021 study found that allowing shop employees to control the music on offer was detrimental to sales.
There's a level of fine-tuning to things like this partly because music can have such diverse and powerful effects on people. Not just on our behaviour but even on how we perceive things.

"We can season food with music or sound," asserts Charles Spence at the University of Oxford. He's spent years conducting experiments on "sonic seasoning" - finding music or sounds that accentuate, say, the spiciness of a curry or the creaminess of a sauce. High-pitched sounds bring out sweetness in chocolate, he says. Low-pitched sounds emphasise bitterness. It sounds scarcely believable but Spence and other researchers have documented these effects in many different controlled experiments over the years. Not all participants experience strong impacts of sonic seasoning, says Spence but, he adds, "In many people [...] who experience it, it's sort of shocking to them because music has nothing to do with taste."

Food for thought

Marketers and restaurant owners have used such insights to try to influence purchases. Playing nature sounds in a restaurant appears to increase people's appreciation of healthy dishes, for example, a 2022 study found. And Spence points to the case of Xin Café, a café and creative space, in Beijing. Inspired by Spence and his colleagues' research, the café deployed cups that played sweet flavour-enhancing music to thirsty customers,
allowing the café to reduce the sugar content of drinks. That sort of intervention could have potential public health benefits, says Spence. While he says it's not clear whether sonic seasoring will work for people again and again, over a long period of time. it is "exciting" to see such experiments in the wild.

People only buy emotion

It's worth remembering that while study after study has found striking associations between particular sounds, or music, and consumer behaviour, this area remains far from completely understood. And only the largest, best-controlled studies may be trustworthy. If you change the music playing in one shop and sales go up, have you accounted for other factors that may have occurred at the same time? Perhaps people got their Christmas bonuses that week. Or, the weather went from torrential rain to bright sunshine, making people want to venture out.

Plus, while the idea that music can measurably affect sales seems counter-intuitive, on another level, maybe it isn't, really.

Brazilian composer Marco Ricciardi, who lives in Australia, has written music for TV stations - including excitement-triggering tunes used on sports programmes. "People never buy anything other than emotions. They are buying what they feel," he quips.

Still, some of the specific findings that turn up are undeniable conversation-starters. Carl-Philip Ahlbom-currently at Florida State University's Herbert Wertheim College of Business - was the lead author on a 2022 paper that described how playing music in a supermarket, versus playing no music, boosted sales. However, the music didn't work at weekends. It was the weary shoppers swinging by the supermarket on the way home from work during the week who were most susceptible to nudging. "When people are more tired, they're more reliant on these background cues," says Ahlbom.

He also says that higher tempo music can make people move around a shop faster, reducing the total time they spend there. In some venues that might be undesirable - potentially harming sales-but in others, such as restaurants keen to rotate tables quickly, it could be a benefit. Research has even indicated that fast-paced telephone hold music can reduce the time that people think they have spent waiting to speak to someone.

There might not be much consumers can do to evade the acoustic nudging that they're exposed to while they shop- unless they try wearing ear plugs or headphones in a desperate attempt to ring-fence their frugality. Meanwhile, for businesses, it seems that getting nudging right is a constant battle of experimentation and re-evaluation. Many of them probably just don't bother.

"I don't think that most [businesses] are tapping into the opportunity here," says Ahlbom. Commercially speaking, that could be a mistake. He stresses that a relatively subtle effect on sales triggered by the introduction of a new playlist could be meaningful - especially if you are a big retailer or food chain with hundreds or thousands of outlets. "Even if, on average, you get a 2 per cent lift," he says, "that's quite a lot of money."