When Jacob Cole, a ‘passenger service agent’ (PSA) on the Docklands Light Railway in London, was asked to inject a bit of personality into his train announcements, he found it came easily. From a mix of pragmatism – a need to slow his words down so that his messages would be understood – and the natural, deep cadences of his voice, the Barry White of the DLR was born. Throw in a catchphrase – “Oh yeahhhh” – and the rail network had a Twitter sensation on their hands.