Alicia Keys gave a surprise performance at Kings Cross Station in London on Monday. br br The American singer-songwriter surprised commuters by playing a handful of her greatest hits. br br The Grammy-winner played on Elton John's piano, which is located on the concourse of the station. br br The crowd cheered and sang along to the songs: "If I Ain't Got You," "Empire State of Mind" and "Lifeline." br br The impromptu gig followed Alicia Key’s performance at Capital FM’s Jingle Bell Ball over the weekend. Report by Fatimaz.