They may be soft rock but Blondie, Eurythmics and Natalie Imbruglia could soon be employed in the business of hard sell after researchers found that playing their hits in stores increased customer satisfaction.

Customers thought queues were shorter, customer service better and the store environment better in shops that played music, despite the fact that nothing had changed bar the introduction of music, a study has found.

But the most "outstanding" finding for Graham Chant, who studied the effect music had on sales, was that customers were none the wiser that they were shopping to, among others, Abba's Dancing Queen.

Retailers have long believed that music affects store ambience but most tend to play bland genres such as easy listening. Mr Chant acknowledged that had heavy metal been tested the outcome might have been different. "There is strong evidence … to support the view that different genres or tempos have different effects on people. I am not too sure what heavy metal might have done."

That man is in pain and he's shouting so loud...