Keys was "on fire" as she performed a string of her hits on Sir Elton John's piano at St. Pancras International Station.
Commuters at London St Pancras were treated to an early and unexpected Christmas gift on Monday, when Alicia Keys graced them with an impromptu performance.
The American singer-songwriter surprised the bustling crowd at the London train terminal when she sang and played a handful of her greatest hits.
Playing on Elton John's piano, which is located on the concourse of the station, the Grammy-winner had the crowd singing along and cheering to her songs, including "If I Ain't Got You," "Empire State of Mind" and "Lifeline."
The surprise gig followed Key's performance at Capital FM’s Jingle Bell Ball, which took place at the weekend at the London O2 Arena.
Watch some of the highlights from her surprise gig in the video player above.