Multi-award winning singer John Legend performed free concert at DTLA's Union Station

LOS ANGELES (KABC) -- For John Legend and his adoring fans Christmas came early at Union Station in Downtown Los Angeles Tuesday.

Recently name sexiest Sexiest Man Alive by "People" magazine, Legend surprised his followers with a free concert, many of them stumbling upon the show by chance.

"We were doing a downtown day, Olvera Street, Chinatown, and now we're here. We literally just walked in," said Tenley Force.

"I saw it on Facebook and was like 'Oh my God, we have to go.' So at two o'clock we just jumped up and came right here," said Christina Palomino of the San Fernando Valley.

The pop up show featuring the Christmas crooner was part of SiriusXM's Dial-up-the-Moment holiday campaign.

Legend sang songs from his Christmas album and filmed a music video inside the iconic train station.

For 500 lucky fans, it was a very special Christmas indeed.