Alicia Keys brightened the commute of train passengers by giving a surprise performance at London’s St Pancras International.The nine-time Grammy Award-winning musician and producer performed some of her biggest hits including Empire State of Mind, If I Ain’t Got You and No One, plus her latest single, Lifeline, which is the first release from soundtrack of the upcoming film The Color Purple.New York native Keys’ appearance was in honour of the release of The Diary of Alicia Keys 20, a special edition of her multi-platinum selling, chart-topping sophomore album, which originally debuted in 2003.Videos captured on Monday (December 11) show Keys swarmed by a crowd who had gathered as she tickled the ivories of the famous piano donated to the station by Sir Elton John.