British singer Florence Welch treated London Underground passengers to an impromptu performance while travelling home after attending a concert on Sunday (20Jan13).

The Florence + The MAChine frontwoman tried to go incognito as she slipped onto a train after watching Kendrick Lamar's gig at the Hammersmith Apollo in the U.K. capital, but she was recognised by fans who began singing her hit You've Got The Love.

Instead of ignoring them, Welch joined in with the group before belting out Lamar's track Backseat Freestyle.

An onlooker tells British newspaper The Sun, "Florence jumped on the Tube (train) after Kendrick and... every carriage was packed. At first she tried to keep a low profile but it didn't take long for a few people to recognise her.

"They started singing You've Got the Love but instead of bailing at the next stop, Florence joined in. It was brilliant.

"She finished You've Got The Love before changing to the Kendrick Lamar song Backseat Freestyle."