What's the link between R. White's Lemonade and the English singer-songwriter Elvis Costello?

In 1973, the 'Secret Lemonade Drinker' advertising campaign was launched by London agency Allen, Brady and Marsh and devised by Rod Allen, who wrote the slogan. The adverts featured actor Julian Chagrin in pyjamas creeping downstairs to raid the fridge for R. Whites Lemonade, only to be caught by his wife, played by Harriet Philpin.[ Ross McManus wrote and sang the advert's song, with his son Declan McManus (later known as Elvis Costello) providing the backing vocals. An alternative, unaired version of the advert featured Costello and his father onstage, as the 'Secret Lemonade Drinker' fantasised about being a rock star.