Les Binet and Sarah Carter get a little bit angry about some of the nonsense they hear around them… like treating music as an afterthought

Recently, we were working on a pitch. A number of teams had come up with ideas which we were honing over the weeks prior to pitch date. One team's idea was a big emotional story about a family set in a South American city. There was no dialogue. At the top of the script were the words 'music: suitably epic'. This creative idea was debated and evolved by the account team, alongside other ideas over a number of days. It wasn't until a week before the pitch, however, that we realised that 'music: suitably epic' was still on the scripts and hadn't been discussed at all. All the chat had been about the action.

We suspect this is quite common. We all know that music matters. In fact, around 90% of international TV ads now use music. But it seems we don't think music matters that much. Hence, the all-too-typical situation of ads going into research with a vague choice of track as the 'right kind of music' to 'give a feel' for the finished ad. Or alternatively, researched music tracks being swapped just before airing because of some legal issue or cost concerns.

Our disregard for the importance of music is evident when we look at the research literature. Of over 48,000 articles on the Warc database, only 10% of them mention music at all, and only 29 (less than 0.1%) discuss it in any detail. But the little research that has been done on music effects suggests these are much greater than we seem to assume.

Research shows that music increases the attention paid to ads and increases recall of brand and message. And we suspect these effects may be very long term. Think about the ads we remember word for word from childhood – it's highly likely they involve music. (Jingles have become rather uncool nowadays – wrongly, in our opinion, because they do work. But that's another article.)

Because music works as an 'access all areas' pass to our System 1 brains, it's perhaps not surprising it has such powerful effects. Research on the implicit effects of advertising shows that ads influence us in ways that may not involve explicit messages at all. And these more implicit, emotional approaches tend to have very broad, long-term effects. As a result, this 'emotional priming' tends to produce very large, long-term sales effects and big profits.

Music is brilliant at creating these emotional reactions that attach directly to brands, thus making them more desirable. Research we have undertaken with Goldsmiths University shows how adding music to an ad increases the implicit brand effect by around 11%.

But what about effects beyond the individual? Advertising and brands work in a social context. People watch TV ads together, and sometimes they talk about them or share them with friends. These social ripples have been shown to massively increase communications effectiveness. And, from Chipotle to the UK retailer John Lewis, it's striking how often music is central to these famous campaigns. In fact, it's estimated that the free media exposure arising from the famous music at the core of John Lewis's Christmas ad each year increases campaign impact by around 75%.

Given all this, it's perhaps not surprising that the IPA Databank shows that TV ads featuring music prominently are significantly more effective than ads that don't -enhancing effectiveness by around 20-30%.

So, possibly, a fifth of the effect of an ad comes from its music – meaning choice of music can easily determine whether or not the ad pays for itself. That's too important to leave to the last minute.