It's a sound that's becoming as familiar to television audiences as our own ringtones or doorbells: an acoustic guitar strums, a piano phrase tinkles, and a wispy female vocal sings a familiar melody as we're gently informed about the benefits of a holiday in the Seychelles or some cut-price kitchenware. In the world of advertising, the fey, unassuming cover version has become remarkably effective, with recent campaigns by John Lewis, Nissan and Twinings much lauded within the industry.
But the sugar-coated approach isn't a hit with everyone; John Lewis's Christmas campaign in particular – featuring a delicate version of The Smiths' "Please, Please, Please Let Me Get What I Want" – came in for sustained battering on social media from those who resent the wave of cute branding that's currently so fashionable. But according to those tasked with producing the soundtracks, there's no immediate let-up in sight.
"It's important for some brands to communicate fragility," says Tamar Carr-Mardindale from the music consultancy Hear No Evil. "It makes people feel comfortable. Using a folky soundtrack has traditionally been one way of doing that – "Heartbeats" by Jose Gonzalez [from a 2005 Sony Bravia campaign] is a good example – but using a female vocal sends out a reassuring, personal message." Hugely popular campaigns in the past decade such as T-Mobile's use of Vashti Bunyan's "Diamond Day" and Apple's repurposing of "1234" by Feist are notable antecedents of this trend, but if anything the music alongside the vocals is becoming even more fragile, according to composer Tom Haines.
"It seems to be all about ukeleles and whistling," he says. "Companies want to give the impression that they're vulnerable, human, just like you – and the way of communicating that is by using fey vocals and ukeleles. I'm asked for that kind of thing three times a week." Simon Elms at Eclectic Music agrees. "It's all about quirky acoustics, very natural sounds. A 'human vibe' is what they want – and it's really popular at the moment. Clapping, whistling and humming."
The gentle sounds may soothe, but the familiar songs make our ears prick up, playing upon what Susan Stone, creative director of Tonic Music, calls the "darling, they're playing our tune" effect. "Communicating familiarity is really important," she says, "and often the original songs can't be used – either because of the cost of licensing, or because the artist doesn't allow it. Brands wanting emotional soundtracks is nothing new, but now many of them look specifically to put an emotional twist on a familiar favourite." In some cases, the success of the pairing has resulted in a chart hit; Ellie Goulding's version of Elton John's "Your Song" hit No 2 in December 2010 after being used by John Lewis, while last year saw "Wherever You Will Go" by Charlene Soraia (originally by The Calling) reach No 3 after a Twinings campaign.
It's part of a feedback loop between trends in music and the world of advertising, according to Simon Elms. "That wispy, very London-sounding female vocal style is really popular at the moment, and advertising just reflects that. Someone will pluck something out of their record collection and say 'We'd like something like this – but not this'". Susan Stone agrees. "For example, Coldplay, Sigur Ros and Radiohead come up all the time in discussions with clients – but of course none of those bands involve themselves with advertising."
Industry insiders talk of a number of upcoming whispery cover versions hitting our screens; the question is how long these unassuming musical soundtracks will remain effective. Writer Dorian Lynskey, who brands such things "Innocentese", detects a growing revulsion to twee art. "As the language becomes more common," he writes on his blog, "more widely mocked, less trusted, it becomes less useful for brands and one day soon – I hope and pray – we will see the end of the Innocents." But not, it seems, for a while yet.